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examples	[ DIR ]	drwxr-xr-x	2025-11-01 13:53
NEWS.Debian.gz	318 B	-rw-r--r--	2025-10-08 11:40
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<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>The Fetchmail FAQ</title>
<meta name="description"
content="Frequently asked questions about fetchmail."/>
<meta name="keywords" content="fetchmail, POP3, IMAP, remote mail"/>
</head>
<body>
<table width="100%" cellpadding="0" summary="Canned page footer">
<tr>
<td width="30%">Back to <a href="index.html">Fetchmail Home
Page</a></td>
<td width="30%" align="right">$Date$</td>
</tr>
</table>

<hr/>
<h1 id="FAQ">Frequently Asked Questions About Fetchmail</h1>

<p><strong>Support? Bug reports?</strong> Please read <a
href="#G3">G3</a> for what information is required to get your problem
solved as quickly as possible.</p>

<p>Note that this FAQ is occasionally updated from the Git repository
and speaks in the past tense ("since") about a fetchmail release that is
not yet available. Please try a release candidate for that version in
case you need the new option.</p>

<p>If you have a question or answer you think ought to be added to
this FAQ list, file it to one of the trackers at <a
    href="https://sourceforge.net/projects/fetchmail/">our SourceForge.net
    project site</a> or post to one of the fetchmail mailing lists (see
below).</p>

<h1 id="Contents">Contents</h1>

<a href="#Contentdetail">Detailed Contents</a><br/>
<a href="#C_G">G. General problems</a><br/>
<a href="#C_B">B. Build-time problems</a><br/>
<a href="#C_F">F. Fetchmail configuration file grammar questions</a><br/>
<a href="#C_C">C. Configuration questions</a><br/>
<a href="#C_T">T. How to make fetchmail play nice with various MTAs</a><br/>
<a href="#C_S">S. How to make fetchmail work with various servers</a><br/>
<a href="#C_I">I. How to fetchmail work with specific ISPs</a><br/>
<a href="#C_K">K. How to set up well-known security and authentication</a><br/>
<a href="#C_R">R. Runtime fatal errors</a><br/>
<a href="#C_H">H. Hangs and lockups</a><br/>
<a href="#C_D">D. Disappearing mail</a><br/>
<a href="#C_M">M. Multidrop-mode problems</a><br/>
<a href="#C_X">X. Mangled mail</a><br/>
<a href="#C_O">O. Other problems</a><br/>

<h1 id="Contentdetail">Detailed Contents</h1>

<h2 id="C_G">General problems</h2>

<a href="#G1">G1. What is fetchmail and why should I bother?</a><br/>
<a href="#G2">G2. Where do I find the latest FAQ and fetchmail sources?</a><br/>
<a href="#G3">G3. Something doesn't work/I think I've found a bug. Will you fix it?</a><br/>
<a href="#G4">G4. I have this idea for a neat feature. Will you add it?</a><br/>
<a href="#G5">G5. I want to make fetchmail remove kept mail after some days.</a><br/>
<a href="#G6">G6. Is there a mailing list for exchanging tips?</a><br/>
<a href="#G7">G7. So, what's this I hear about a fetchmail paper?</a><br/>
<a href="#G8">G8. What is the best server to use with fetchmail?</a><br/>
<a href="#G9">G9. What is the best mail program to use with fetchmail?</a><br/>
<a href="#G10">G10. How can I avoid sending my password en clair?</a><br/>
<a href="#G11">G11. Is any special configuration needed to use a dynamic IP address?</a><br/>
<a href="#G12">G12. Is any special configuration needed to use firewalls?</a><br/>
<a href="#G13">G13. Is any special configuration needed to <em>send</em> mail?</a><br/>
<a href="#G14">G14. Is fetchmail Y2K-compliant?</a><br/>
<a href="#G15">G15. Is there a way in fetchmail to support disconnected IMAP mode?</a><br/>
<a href="#G16">G16. How will fetchmail perform under heavy loads?</a><br/>

<h2 id="C_B">Build-time problems</h2>

<a href="#B1"><strike>B1. Make coughs and dies when building on FreeBSD.</strike></a><br/>
<a href="#B2">B2. Lex bombs out while building the fetchmail lexer.</a><br/>
<a href="#B3">B3. I get link failures when I try to build fetchmail.</a><br/>
<a href="#B4">B4. I get build failures in the intl directory.</a><br/>

<h2 id="C_F">Fetchmail configuration file grammar questions</h2>

<a href="#F1">F1. Why does my old .fetchmailrc no longer work?</a><br/>
<a href="#F2"><strike>F2. The .fetchmailrc parser won't accept my all-numeric user name.</strike></a><br/>
<a href="#F3"><strike>F3. The .fetchmailrc parser won't accept my host or username beginning with 'no'.</strike></a><br/>
<a href="#F4">F4. I'm getting a 'parse error' message I don't understand.</a><br/>

<h2 id="C_C">Configuration questions</h2>

<a href="#C1">C1. Why do I need a .fetchmailrc when running as root
on my own machine?</a><br/>
<a href="#C2">C2. How can I arrange for a fetchmail daemon to get
killed when I log out?</a><br/>
<a href="#C3">C3. How do I know what interface and address to use
with --interface?</a><br/>
<a href="#C4">C4. How can I set up support for sendmail's anti-spam
features?</a><br/>
<a href="#C5">C5. How can I poll some of my mailboxes more/less
often than others?</a><br/>
<a href="#C6">C6. Fetchmail works OK started up manually, but not
from an init script.</a><br/>
<a href="#C7">C7. How can I forward mail to another
host?</a><br/>
<a href="#C8">C8. Why is "NOMAIL" an error?/I frequently get messages
from cron!</a><br/>

<h2 id="C_T">How to make fetchmail play nice with various MTAs</h2>

<a href="#T1">T1. How can I use fetchmail with sendmail?</a><br/>
<a href="#T2">T2. How can I use fetchmail with qmail?</a><br/>
<a href="#T3">T3. How can I use fetchmail with exim?</a><br/>
<a href="#T4">T4. How can I use fetchmail with smail?</a><br/>
<a href="#T5">T5. How can I use fetchmail with SCO's MMDF?</a><br/>
<a href="#T6">T6. How can I use fetchmail with Lotus Notes?</a><br/>
<a href="#T7">T7. How can I use fetchmail with Courier IMAP?</a><br/>
<a href="#T8">T8. How can I use fetchmail with vbmailshield?</a><br/>

<h2 id="C_S">How to make fetchmail work with various servers</h2>

<a href="#S1"><strike>S1. How can I use fetchmail with qpopper?</strike></a><br/>
<a href="#S2">S2. How can I use fetchmail with Microsoft Exchange?</a><br/>
<a href="#S3">S3. How can I use fetchmail with HP OpenMail?</a><br/>
<a href="#S4">S4. How can I use fetchmail with Novell GroupWise?</a><br/>
<a href="#S5">S5. How can I use fetchmail with InterChange?</a><br/>
<a href="#S6">S6. How can I use fetchmail with MailMax?</a><br/>
<a href="#S7">S7. How can I use fetchmail with FTGate?</a><br/>

<h2 id="C_I">How to fetchmail work with specific ISPs</h2>

<a href="#I1">I1. How can I use fetchmail with Compuserve RPA?</a><br/>
<a href="#I2">I2. How can I use fetchmail with Demon Internet's SDPS?</a><br/>
<a href="#I3">I3. How can I use fetchmail with usa.net's servers?</a><br/>
<a href="#I4">I4. How can I use fetchmail with geocities POP3 servers?</a><br/>
<a href="#I5">I5. How can I use fetchmail with Hotmail or Lycos Webmail?</a><br/>
<a href="#I6">I6. How can I use fetchmail with MSN?</a><br/>
<a href="#I7">I7. How can I use fetchmail with SpryNet?</a><br/>
<a href="#I8">I8. How can I use fetchmail with comcast.net or other
    Maillennium servers?</a><br/>
<a href="#I9">I9. How can I use fetchmail with GMail/Google Mail?</a><br/>

<h2 id="C_K">How to set up well-known security and authentication
methods</h2>

<a href="#K1">K1. How can I use fetchmail with SOCKS?</a><br/>
<a href="#K2">K2. How can I use fetchmail with IPv6 and IPsec?</a><br/>
<a href="#K3">K3. How can I get fetchmail to work with ssh?</a><br/>
<a href="#K4">K4. What do I have to do to use the IMAP-GSS protocol?</a><br/>
<a href="#K5">K5. How can I use fetchmail with SSL or TLS?</a><br/>
<a href="#K6">K6. How can I tell fetchmail not to try TLS if the server
    advertises it? Why does fetchmail use STARTTLS, STLS, TLS or SSL even though not configured?</a><br/>

<h2 id="C_R">Runtime fatal errors</h2>

<a href="#R1">R1. Fetchmail isn't working, and -v shows 'SMTP
connect failed' messages.</a><br/>
<a href="#R2">R2. When I try to configure an MDA, fetchmail doesn't
work.</a><br/>
<a href="#R3">R3. Fetchmail dumps core when given an invalid rc
file.</a><br/>
<a href="#R4"><strike>R4. Fetchmail dumps core in -V mode, but operates
    normally otherwise.</strike></a><br/>
<a href="#R5">R5. Running fetchmail in daemon mode doesn't
work.</a><br/>
<a href="#R6">R6. Fetchmail randomly dies with socket errors.</a><br/>
<a href="#R7">R7. Fetchmail running as root stopped working after
an OS upgrade</a><br/>
<a href="#R8">R8. Fetchmail is timing out after fetching certain
messages but before deleting them</a><br/>
<a href="#R9">R9. Fetchmail is timing out during message fetches</a><br/>
<a href="#R10"><strike>R10. Fetchmail is dying with SIGPIPE.</strike></a><br/>
<a href="#R11">R11. My server is hanging or emitting errors on CAPA.</a><br/>
<a href="#R12">R12. Fetchmail isn't working and reports getaddrinfo
    errors.</a><br />
<a href="#R13">R13. What does "Interrupted system call" mean?</a><br />
<a href="#R14">R14. Since upgrading fetchmail/OpenSSL, I can no longer connect!</a><br />
<a href="#R15">R15. Help, I'm getting Authorization failure!</a><br />

<h2 id="C_H">Hangs and lockups</h2>

<a href="#H1">H1. Fetchmail hangs when used with pppd.</a><br/>
<a href="#H2">H2. Fetchmail hangs during the MAIL FROM
exchange.</a><br/>
<a href="#H3">H3. Fetchmail hangs while fetching mail.</a><br/>

<h2 id="C_D">Disappearing mail</h2>

<a href="#D1">D1. I think I've set up fetchmail correctly, but I'm
not getting any mail.</a><br/>
<a href="#D2">D2. All my mail seems to disappear after a dropped
connection.</a><br/>
<a href="#D3">D3. Mail that was being fetched when I interrupted my
fetchmail seems to have been vanished.</a><br/>

<h2 id="C_M">Multidrop-mode problems</h2>

<a href="#M0">M0. What about multidrop, anyways?</a><br />
<a href="#M1">M1. I've declared local names, but all my multidrop
mail is going to root anyway.</a><br/>
<a href="#M2">M2. I can't seem to get fetchmail to route to a local
domain properly.</a><br/>
<a href="#M3">M3. I tried to run a mailing list using multidrop,
and I have a mail loop!</a><br/>
<a href="#M4"><strike>M4. My multidrop fetchmail seems to be having DNS
    problems.</strike></a><br/>
<a href="#M5">M5. I'm seeing long DNS delays before each message is
processed.</a><br/>
<a href="#M6">M6. How do I get multidrop mode to work with
majordomo?</a><br/>
<a href="#M7">M7. Multidrop mode isn't parsing envelope addresses
from my Received headers as it should.</a><br/>
<a href="#M8">M8. Users are getting multiple copies of
messages.</a><br/>

<h2 id="C_X">Mangled mail</h2>

<a href="#X1">X1. Spurious blank lines are appearing in the headers
of fetched mail.</a><br/>
<a href="#X2">X2. My mail client can't see a Subject
line.</a><br/>
<a href="#X3">X3. Messages containing "From" at start of line are
being split.</a><br/>
<a href="#X4">X4. My mail is being mangled in a new and different
way.</a><br/>
<a href="#X5"><strike>X5. Using POP3, retrievals seems to be fetching too
much!</strike></a><br/>
<a href="#X6">X6. My mail attachments are being dropped or
mangled.</a><br/>
<a href="#X7">X7. Some mail attachments are hanging
fetchmail.</a><br/>
<a href="#X8">X8. A spurious ) is being appended to my
messages.</a><br/>
<a href="#X9">X9. Missing "Content-Transfer-Encoding" header
with Domino IMAP</a><br/>
<a href="#X10">X10. Fetchmail delivers partial messages</a><br/>

<h2 id="C_O">Other problems</h2>

<a href="#O1">O1. The --logfile option doesn't work if the logfile
doesn't exist.</a><br/>
<a href="#O2">O2. Every time I get a POP or IMAP message the header
is dumped to all my terminal sessions.</a><br/>
<a href="#O3">O3. Does fetchmail reread its rc file every poll
cycle?</a><br/>
<a href="#O4">O4. Why do deleted messages show up again when I take
a line hit while downloading?</a><br/>
<a href="#O5">O5. Why is fetched mail being logged with my name,
not the real From address?</a><br/>
<a href="#O6">O6. I'm seeing long sendmail delays or hangs near the
start of each poll cycle.</a><br/>
<a href="#O7">O7. Why doesn't fetchmail deliver mail in date-sorted
order?</a><br/>
<a href="#O8">O8. I'm using pppd. Why isn't my monitor option
working?</a><br/>
<a href="#O9">O9. Why does fetchmail keep retrieving the same
messages over and over?</a><br/>
<a href="#O10"><strike>O10. Why is the received date on all my messages the
    same?</strike></a><br/>
<a href="#O11">O11. I keep getting messages that say "Repoll
immediately" in my logs.</a><br/>
<a href="#O12">O12. Fetchmail no longer expunges mail on a 451 SMTP response.</a><br/>
<a href="#O13">O13. I want timestamp information in my fetchmail logs.</a><br/>
<a href="#O14">O14. Fetchmail no longer deletes oversized mails with
    --flush.</a><br/>
<a href="#O15">O15. Fetchmail always retains the first message in the
    mailbox.</a><br/>
<a href="#O16">O16. Why is the Fetchmail FAQ only available in
	ISO-216 A4 format? How do I get the FAQ in Letter
	format?</a><br/>
<a href="#O17">O17. Linux logs "TCP(fetchmail:...): Application bug, race
    in MSG_PEEK."</a><br/>

<hr/>
<h1 id="G">General problems</h1>
<h2><a id="G1" name="G1">G1. What is fetchmail and why should I
bother?</a></h2>

<p>Fetchmail is a one-stop solution to the remote mail retrieval
problem for Unix machines, quite useful to anyone with an
intermittent or dynamic-IP connection to a remote mailserver, SLIP or
PPP dialup, or leased line when SMTP isn't desired. Fetchmail can
collect mail using any variant of POP or IMAP and forwards to a the
local SMTP (via TCP socket) or LMTP (via TCP or Unix socket) listener or
into an MDA program, enabling all the normal
forwarding/filtering/aliasing mechanisms that would apply to local mail
or mail arriving via a full-time TCP/IP connection.</p>

<p>Fetchmail is not a toy or a coder's learning exercise, but an
industrial-strength tool capable of transparently handling every
retrieval demand from those of a simple single-user ISP connection
up to mail retrieval and rerouting for an entire client domain.
Fetchmail is easy to configure, unobtrusive in operation, powerful,
feature-rich, and well documented.</p>

<p>Fetchmail is <a href="https://opensource.org/">Open Source</a>
Software. The openness of the sources enables you to review and
customize the code, and contribute your changes.</p>

<p>A former fetchmail maintainer once claimed that Open Source software
were the strongest quality assurance, but the current maintainers do not
believe that open source alone is a criterion for quality &ndash; <a
    href="fetchmail-SA-2005-01.txt">the remotely exploitable POP3
    vulnerability (CVE-2005-2335)</a> lingered undiscovered in
fetchmail's code for years, which is a hint that open source code does
not audit itself.</p>

<p>Fetchmail is licensed under the <a
href="https://www.gnu.org/licenses/old-licenses/gpl-2.0.html">GNU General Public
License v2</a>. Details, including an exception that allows linking
against OpenSSL, are in the COPYING file in the fetchmail
distribution.</p>

<p>If you found this FAQ in the distribution, see the README for
fetchmail's full feature list.</p>

<h2><a id="G2" name="G2">G2. Where do I find the latest FAQ and
fetchmail sources?</a></h2>

<p>The latest HTML FAQ is available alongside the latest fetchmail
sources at the fetchmail home page: <a
href="http://www.fetchmail.info/">http://www.fetchmail.info/</a>.
We used to have new versions in the iBiblio site, but they have stopped accepting uploads, and the fetchmail versions on iBiblio are outdated.</p>

<p>A text dump of this FAQ is included in the fetchmail
distribution. Because it freezes at distribution release time, it
may not be completely current.</p>

<p>The fetchmail sources are also available in the Git repositories at <a href="https://gitlab.com/fetchmail/fetchmail">https://gitlab.com/fetchmail/fetchmail</a> and <a href="https://sourceforge.net/p/fetchmail/git/">https://sourceforge.net/p/fetchmail/git/</a>.</p>

<p>Note the Git branches:</p>
<ul>
	<li>legacy_63 (discontinued, unsupported old branch for 6.3.x releases)</li>
	<li>legacy_64 (stable 6.4.x releases),</li>
	<li>legacy_6x (near-future 6.5.x development),</li>
	<li>next (mid-term future 7.x.x development)</li>
</ul>
<p>As of 2020-06-21, there no longer is a <em>master</em> branch. next was renamed to old-next, and <em>master</em> was renamed to <strong>next</strong>.</p>

<h2><a id="G3" name="G3">G3. Something does not work/I think I've found a bug. Will you fix it?</a></h2>

<p>The first thing you should to is to upgrade to the newest version of
fetchmail, and then see if the problem reproduces. So you'll probably
save us both time if you upgrade and test with <a href="#G2">the latest
    version</a> <em>before</em> sending in a bug report.</p>

<p>Bugs will be fixed, provided you include enough diagnostic information
for me to go on. Send bugs to <a
href="mailto:fetchmail-users@lists.sourceforge.net">fetchmail-users</a>.
When sending bugs or asking for help, please <strong>do not make up
    information except your password</strong> and please
<strong>report</strong> the following:</p>

<ol>
<li>Your operating system.</li>

<li>Your compiler version, if you built from source; otherwise, the
name and origin of the RPM or other binary package you
installed.</li>

<li>The name and version of the SMTP listener or MDA you are
forwarding to.</li>

<li>Any command-line options you used.</li>

<li>The output of <kbd>env LC_ALL=C fetchmail -V</kbd> called with
whatever other command-line options you used.</li>

<li><strong>The output of <kbd>env LC_ALL=C fetchmail --nodetach -vvv
--nosyslog</kbd> with whatever other command-line options you use
routinely.</strong>
 <p>It is very important that the transcript include your
POP/IMAP server's greeting line, so I can identify it in case of server
problems. This transcript will not reveal your passwords, which are
specially masked out precisely so transcripts can be passed around.</p>
</li>
</ol>

<p>If you have FTP access to your remote mail account, and you have
any suspicion that the bug was triggered by a particular message,
please include a copy of the message that triggered the bug.</p>

<p>If your bug is something that used to work but stopped working
when you upgraded, then you can help pin the bug down by bisecting, i. e. trying <a
href="http://sourceforge.net/p/fetchmail/git/ci/legacy_63/tree/">intermediate versions
of fetchmail</a> until you identify the revision that broke your
feature. The smart way to do this is by binary search on the
version sequence. First, try the version halfway between your last
good one and the current one. If it works, the failure was
introduced in the upper half of the sequence; if it doesn't, the
failure was introduced in the lower half. Now bisect that half in
the same way. In a very few tries, you should be able to identify
the exact adjacent pair of versions between which your bug was
introduced. <strong>Please</strong> include session transcripts (as
described in the last bullet point above) of <strong>both
the working and failing versions.</strong> Often, the source of the problem
can instantly identified by looking at the differences in protocol
transactions.</p>

<p>It may helpful if you include your .fetchmailrc file, but not
necessary unless your symptom seems to involve an error in
configuration parsing. If you do send in your .fetchmailrc, mask
the passwords first! Otherwise, fetchmail -V &ndash; as directed above
&ndash; will usually suffice.</p>

<p>If fetchmail seems to run and fetch mail, but the headers look
mangled (that is, headers are missing or blank lines are inserted
in the headers) then read the FAQ items in section <a
href="#X1">X</a> before submitting a bug report. Pay special
attention to the item on <a href="#generic_mangling">diagnosing
mail mangling</a>. There are lots of ways for other programs in the
mail chain to screw up that look like fetchmail's fault, but you
may be able to fix these by tweaking your configuration.</p>

<p>If the bug involves a core dump or hang, a gdb stack trace is
good to have. (Bear in mind that you can attach gdb to a running
but hung process by giving the process ID as a second argument.)
You will need to reconfigure with:</p>

<pre>
CFLAGS=-g LDFLAGS=" " ./configure
</pre>

<p>Then rebuild in order to generate a version that can be
traced with a debugger such as gdb, dbx or idb.</p>

<p>Best of all is a mail file which, when fetched, will reproduce
the bug under the latest (current) version.</p>

<p>Any bug I can reproduce will usually get fixed quite quickly.
Bugs I can't reproduce are a crapshoot. If the solution isn't obvious
when I first look, it may evade me for a long time (or to put it another
way, fetchmail is well enough tested that the easy bugs have long since
been found). So if you want your bug fixed rapidly, it is not just
sufficient but <em>necessary</em> that you give me a way to
easily reproduce it.</p>

<h2><a id="G4" name="G4">G4. I have this idea for a neat feature.
Will you add it?</a></h2>

<p>If it's reasonable for fetchmail and cannot be solved with reasonable
effort outside of fetchmail, perhaps.</p>

<p>You can do spam filtering better with procmail or maildrop on
the server side and (if you're the server sysadmin) sendmail.cf
domain exclusions. If you really want fetchmail to do it from the
client side, use a <code>preconnect</code> command to call
<a href='http://mailfilter.sourceforge.net/'>mailfilter</a>.</p>

<p>You can do other policy things better with the
<code>mda</code> option and script wrappers around fetchmail. If
it's a prime-time-vs.-non-prime-time issue, ask yourself whether a
wrapper script called from crontab would do the job.</p>

<p>fetchmail's first job is transport though, and it should do this
well. If a feature would cause fetchmail to deteriorate in other
respects, the feature will probably not be added.</p>

<p>For reasons fetchmail doesn't have other commonly-requested
features (such as password encryption, or multiple concurrent polls
from the same instance of fetchmail) see <a
href="esrs-design-notes.html">ESR's design
notes</a>. Note that this document is partially obsoleted by the
<a href="design-notes.html">updated design notes.</a></p>

<h2><a id="G5" name="G5">G5. I want to make fetchmail remove kept mail after
some days.</a></h2>

<p>The second-most-requested feature for fetchmail, after
content-based filtering, is the ability to have it remove messages
from a maildrop after N days, typically to be used with the
<code>keep</code> option. Several messaging programs with graphical
user interface support this feature.</p>

<p>This feature is not yet implemented. It may be at a future date,
spare time of developers permitting.</p>

<p>For the time being, the contrib/ directory contains some <em>unsupported</em>
  tools that may help, namely mold-remover.py and delete-later.</p>

<h2><a id="G6" name="G6">G6. Is there a mailing list for exchanging
tips?</a></h2>

<p>There is a fetchmail-users list
&lt;fetchmail-users@lists.sourceforge.net&gt;
for bug reports and people who want to discuss configuration issues of
fetchmail. Please see <a href="#G3">G3 above for information you need to
report.</a></p>
<p>Then there is a fetchmail-devel list
&lt;fetchmail-devel@lists.sourceforge.net&gt; for people who want to discuss
fixes and improvements in fetchmail and help co-develop it.</p>
<p>Finally, there is also an announcements-only list,
&lt;fetchmail-announce@lists.sourceforge.net&gt;.</p>

<p>For all lists, see <a href="https://sourceforge.net/p/fetchmail/mailman/">https://sourceforge.net/p/fetchmail/mailman/</a> for subscription, archive and search links.</p>

<h2><a id="G7" name="G7">G7. So, what's this I hear about a
fetchmail paper?</a></h2>

<p>Eric S. Raymond also considered fetchmail development a sociological
experiment, an extended test to see if his theory about the critical
features of the Linux development model was correct.</p>

<p>He considers the experiment a success. He wrote a paper about it titled <a
href="http://www.catb.org/~esr/writings/cathedral.html">The
Cathedral and the Bazaar</a> which was first presented at Linux
Kongress '97 in Bavaria and very well received there. It was also
given at Atlanta Linux Expo, Linux Pro '97 in Warsaw, and the first
Perl Conference, at UniForum '98, and was the basis of an invited
presentation at Usenix '98. The folks at Netscape told ESR it helped
them decide to <a
href="http://wp.netscape.com/newsref/pr/newsrelease558.html">give
away the source for Netscape Communicator</a>.</p>

<p>If you're reading a non-HTML dump of this FAQ, you can find the
paper on the Web with a search for that title.</p>

<h2><a id="G8" name="G8">G8. What is the best server to use with
fetchmail?</a></h2>

<p>Fetchmail will work with any POP, IMAP, ETRN, or ODMR server
that conforms to the relevant standards/RFCs (and even some outright
broken ones like <a href="#S2">Microsoft Exchange</a> and <a
    href="#S6">Novell GroupWise</a>). This doesn't mean it works equally
well with all, however. POP2 servers, and POP3 servers without UIDL,
limit fetchmail's capabilities in various ways described on the manual
page.</p>

<p>Most modern Unixes (and effectively all Linux/*BSD systems) come
with POP3 support preconfigured (but beware of the horribly broken
POP3 server mentioned in <a href="#D2">D2</a>). An increasing
minority also feature IMAP (you can detect IMAP support by using the
'Probe for supported protocols' function in the fetchmailconf
utility - unfortunately it does not detect SSL-wrapped variants).</p>

<p>If you have the option, we recommend using or installing an
IMAP4rev1 or UIDL-capable POP3 server.</p>

<p>A decent POP3/IMAP server that has recently become popular is <a
    href="https://www.dovecot.org/">Dovecot</a>.</p>

<h2><a id="G9" name="G9">G9. What is the best mail program to use
with fetchmail?</a></h2>

<p>Fetchmail will work with all popular <a href="#T1">mail
transport programs</a>. It also doesn't care which user agent you
use, and user agents are as a rule almost equally indifferent to
how mail is delivered into your system mailbox. So any of the
popular Unix mail agents &ndash; <a
href="http://www.instinct.org/elm/">elm</a>, <a
href="http://alpine.x10host.com/alpine/">alpine</a> (a rewrite of pine), <a
href="https://www.nongnu.org/nmh/">nmh</a> (the successor to MH), or
<a href="http://www.mutt.org/">mutt</a> &ndash; will work fine with
fetchmail.</p>

<p>All this having been said, I can't resist putting in a discreet
plug for <a href="http://www.mutt.org">mutt</a>.  Mutt's interface
is only a little different from that of its now-moribund ancestor
elm, but its flexibility and excellent handling of MIME and PGP put it
in a class by itself. You won't need its built-in POP3 support, though.
</p>

<h2><a id="G10" name="G10">G10. How can I avoid sending my password
en clair?</a></h2>

<p>You need to ask whether password
encryption alone will really address your security exposure. If you
think you might be snooped between server and client, it's better
to use end-to-end encryption such as GnuPG (see below) on your whole
mail stream so none of it can be read.</p>

<p>Then, you can use <a href="#K5">SSL or TLS</a> for complete
end-to-end encryption if you have a TLS-enabled mailserver.</p>

<p>One of the advantages of
fetchmail over conventional SMTP-push delivery is that you may be able
to arrange encryption by using ssh(1); see <a href="#K3">K3</a>.</p>

<p>Note that ssh is not a complete privacy solution either, as your
mail could have been snooped in transit to your POP server from
wherever it originated. For best security, agree with your
correspondents to use a tool such as <a
    href="https://www.gnupg.org/">GnuPG</a> (Gnu Privacy Guard) or PGP
(Pretty Good Privacy).</p>

<p>If ssh/sshd isn't available, or you find it too complicated for
you to set up, password encryption will at least keep a malicious
cracker from deleting your mail, and require him to either tap your
connection continuously or crack root on the server in order to
read it.</p>

<p>You can deduce what encryptions your mail server has available
by looking at the server greeting line (and, for IMAP, the response
to a CAPABILITY query). Do a <code>fetchmail -v</code> to see
these, or telnet direct to the server port (110 for POP3, 143 for
IMAP).</p>

<p>Your server may have CRAM-MD5 support built in.</p>

<p>The POP3 facility you are most likely to have available is APOP.
This is a POP3 feature supported by many servers (fetchmailconf's
autoprobe facility will detect it and tell you if you have it). If
you see something in the greeting line that looks like an
angle-bracket-enclosed Internet address with a numeric left-hand
part, that's an APOP challenge (it will vary each time you log in).
For some hosts, you need to register a secret on the host (using
<code>popauth(8)</code> or some program like that). Specify the
secret as your password in your .fetchmailrc; it will be used to
encrypt the current challenge, and the encrypted form will be sent
back the the server for verification. Note that APOP is no longer
considered secure since March 2007.</p>

<p>Alternatively, you may have Kerberos available. This may require
you to set up some magic files in your home directory on your
client machine, but means you can omit specifying any password at
all.</p>

<p>Fetchmail supports two different Kerberos schemes. One is a POP3
variant called KPOP; consult the documentation of your mail server
to see if you have it (one clue is the string "krb-IV" in the
greeting line on port 110). The other is an IMAP and POP3 facility
described by RFC1731 and RFC1734. You can tell if this one is
present by looking for AUTH=KERBEROS_V4 in the CAPABILITY
response.</p>

<p>Your POP3 server may have the RFC1938 OTP capability to use
one-time passwords. To check this, look for the string "otp-" in the
greeting line. If you see it, and your fetchmail was built with
OPIE support compiled in (see the distribution INSTALL file),
fetchmail will detect it also. When using OTP, you will specify a
password but it will not be sent en clair.</p>

<h2><a id="G11" name="G11">G11. Is any special configuration needed
to use a dynamic IP address?</a></h2>

<p>Yes. In order to avoid giving indigestion to certain picky MTAs
(notably <a href="#T3">exim</a>), fetchmail always makes the RCPT&nbsp;TO
address it feeds the MTA a fully qualified one with a hostname
part. Normally it does this by appending @ and "localhost", but
when you are using Kerberos or ETRN mode it will append @ and your
machine's fully-qualified domain name (FQDN).</p>

<p>Appending the FQDN can create problems when fetchmail is running
in daemon mode and outlasts the dynamic IP address assignment your
client machine had when it started up.</p>

<p>Since the new IP address (looked up at RCPT&nbsp;TO interpretation
time) doesn't match the original, the most benign possible result
is that your MTA thinks it's seeing a relaying attempt and refuses.
More frequently, fetchmail will try to connect to a nonexistent
host address and time out. Worst case, you could end up forwarding your
mail to the wrong machine!</p>

<p>Use the <code>smtpaddress</code> option to force the appended
hostname to one with a (fixed) IP address of 127.0.0.1 in your
<code>/etc/hosts</code>. (The name 'localhost' will usually work;
or you can use the IP address itself.)</p>

<p>Only one fetchmail option interacts directly with your IP
address, '<code>interface</code>'. This option can be used to set
the gateway device and restrict the IP address range fetchmail will
use. Such a restriction is sometimes useful for security reasons,
especially on multihomed sites. See <a href="#C3">C3</a>.</p>

<p>I recommend against trying to set up the <code>interface</code>
option when initially developing your poll configuration &ndash; it's
never necessary to do this just to get a link working. Get the link
working first, observe the actual address range you see on
connections, and add an <code>interface</code> option (if you need
one) later.</p>

<p>You can't use ETRN if you have a dynamic IP address (your ISP
changes your IP address occasionally, possibly with every connect).
You need to have your own registered domain and a definite IP
address registered for that domain. The server needs to be
configured to accept mail for your domain but then queue it to
forward to your machine. ETRN just tells to server to flush its
queue for your domain. Fetchmail doesn't actually get the mail in
that case.</p>

<p>You can use On-Demand Mail Relay (ODMR) with a dynamic IP
address; that's what it was designed for, and it provides
capabilities very similar to ETRN. Unfortunately ODMR servers are
still not yet widely deployed, as of 2006.</p>

<p>If you're using a dynamic-IP configuration, one other
(non-fetchmail) problem you may run into with outgoing mail is that
some sites will bounce your email because the hostname you're giving
them isn't real (and doesn't match what they get doing a reverse
DNS on your dynamically-assigned IP address). If this happens, you
need to hack your sendmail so it masquerades as your host.
Setting</p>

<pre>
DMsmarthost.here
</pre>

<p>in your <code>sendmail.cf</code> will work, or you can set</p>

<pre>
MASQUERADE_AS(smarthost.here)
</pre>

<p>in the m4 configuration and do a reconfigure. (In both cases,
replace <code>smarthost.here</code> with the actual name of your
mailhost.) See the <a
href="http://www.lege.com/sendmail-FAQ.txt">sendmail FAQ</a> for
more details.</p>

<h2><a id="G12" name="G12">G12. Is any special configuration needed
to use firewalls?</a></h2>

<p>No. You can use fetchmail with SOCKS, the standard tool for
indirecting TCP/IP through a firewall. You can find out about
SOCKS, and download the SOCKS software including server and client
code, at the <strike>http://www.socks.nec.com/</strike> <i>Link defunct</i> SOCKS distribution
site.</p>

<p>The specific recipe for using fetchmail with a firewall is at <a
href="#K1">K1</a></p>

<h2><a id="G13" name="G13">G13. Is any special configuration needed
to <em>send</em> mail?</a></h2>

<p>A user asks: but how do we send mail out to the POP3 server? Do
I need to implement another tool or will fetchmail do this too?</p>

<p>Fetchmail only handles the receiving side. The sendmail or other
preinstalled MTA on your client machine will handle sending mail
automatically; it will ship mail that is submitted while the
connection is active, and put mail that is submitted while the
connection is inactive into the outgoing queue.</p>

<p>Normally, sendmail is also run periodically (every 15 minutes on
most Linux systems) in a mode that tries to ship all the mail in
the outgoing queue. If you have set up something like pppd to
automatically dial out when your kernel is called to open a TCP/IP
connection, this will ensure that the mail gets out.</p>

<h2><a id="G14" name="G14">G14. Is fetchmail
Y2K-compliant?</a></h2>

<p>Fetchmail is fully Y2K-compliant.</p>

<p>Fetchmail could theoretically have problems when the 32-bit
time_t counters roll over in 2038, but I doubt it. Timestamps
aren't used for anything but log entry generation. Anyway, if you
aren't running on a 64-bit machine by then, you'll deserve to
lose.</p>

<h2><a id="G15" name="G15">G15. Is there a way in fetchmail to
support disconnected IMAP mode?</a></h2>

<p>No. Fetchmail is a mail transport agent, best understood as a
protocol gateway between POP3/IMAP servers and SMTP. Disconnected
operation requires an elaborate interactive client. It's a very
different problem.</p>

<h2><a id="G16" name="G16">G16. How will fetchmail perform under
heavy loads?</a></h2>

<p>Fetchmail streams message bodies line-by-line; the most core it
ever requires per message is enough memory to hold the RFC822
header, and that storage is freed when body processing begins. It
is, accordingly, quite economical in its use of memory. It will store
the UID or UIDL data in core however, which can become considerable if
you are keeping lots of messages on the server.</p>

<p>After startup time, a fetchmail running in daemon mode stats its
configuration file once per poll cycle to see whether it has
changed and should be rescanned. Other than that, a fetchmail in
normal operation doesn't touch the disk at all; that job is left up
to the MTA or MDA the fetchmail talks to.</p>

<p>Fetchmail's performance is usually bottlenecked by latency on
the POP server or (less often) on the TCP/IP link to the server.
This is not a problem readily solved by tuning fetchmail, or even
by buying more TCP/IP capacity (which tends to improve bandwidth
but not necessarily latency).</p>

<hr/>
<h1>Build-time problems</h1>
<h2><a id="B1" name="B1"><strike>B1. Make coughs and dies when building on
FreeBSD.</strike></a></h2>

<p style="font-style:italic;">As of release 6.3.0, fetchmail's
Makefile[.in] should work flawlessly with BSD's portable make used on
FreeBSD.</p>

<h2><a id="B2" name="B2">B2. Lex bombs out while building the
fetchmail lexer.</a></h2>

<p>fetchmail 6.3.0 and newer ship with the lexer and parser in .c
formats, so you do not need to use lex unless you hacked the .l or .y
files.</p>

<p>fetchmail's lexer has been developed with GNU flex and uses some of
its specialties, so the lexer cannot be compiled with the lex tools
shipped by some UNIX vendors (HP, SGI, Sun).</p>

<h2><a id="B3" name="B3">B3. I get link failures when I try to
build fetchmail.</a></h2>

<p>If you get errors resembling these:</p>

<pre>
mxget.o(.text+0x35): undefined referenceto '__res_search'
mxget.o(.text+0x99): undefined reference to '__dn_skipname'
mxget.o(.text+0x11c): undefined reference to '__dn_expand'
mxget.o(.text+0x187): undefined reference to '__dn_expand'
make: *** [fetchmail] Error 1
</pre>

<p>then you must add "-lresolv" to the LOADLIBS line in your
Makefile once you have installed the 'bind' package.</p>

<p>If you get link errors involving <tt>dcgettext</tt>, like
these:</p>

<pre>
rcfile_y.o: In function 'yyparse':
rcfile_y.o(.text+0x3aa): undefined reference to 'dcgettext__'
rcfile_y.o(.text+0x4f2): undefined reference to 'dcgettext__'
rcfile_y.o(.text+0x5ee): undefined reference to 'dcgettext__'
rcfile_y.o: In function 'yyerror':
rcfile_y.o(.text+0xc7c): undefined reference to 'dcgettext__'
rcfile_y.o(.text+0xcc8): undefined reference to 'dcgettext__'
rcfile_y.o(.text+0xdf9): more undefined references to 'dcgettext__' follow
</pre>

<p>install an up to date version of GNU gettext, reconfigure and rebuild
fetchmail. If that does not help, reconfigure with '--disable-nls' added
to the "./configure" command and rebuild.</p>

<h2><a id="B4" name="B4">B4. I get build failures in the intl
directory.</a></h2>

<p>Reconfigure with <tt>--disable-nls</tt> and recompile.</p>

<hr/>
<h1>Fetchmail configuration file grammar questions</h1>
<h2><a id="F1" name="F1">F1. Why does my old .fetchmailrc file no
longer work?</a></h2>

<h3>If your file predates 6.4.0</h3>

<p>Note that fetchmail no longer supports SSLv2, and you should
avoid SSLv3 or TLSv1.0 if possible.</p>

<h3>If your file predates 6.3.0</h3>

<p>The <tt>netsec</tt> option was discontinued and needs to be
removed.</p>

<h3>If your file predates 5.8.9</h3>

<p>If you were using ETRN mode, change your <tt>smtphost</tt>
option to a <tt>fetchdomains</tt> option.</p>

<h3>If your file predates 5.8.3</h3>

<p>The <tt>'via localhost'</tt> special case for use with ssh tunnelling is
gone. Use the <tt>%h</tt> feature of <tt>plugin</tt> instead.</p>

<h3>If your file predates 5.6.8</h3>

<p>In 5.6.8, the <tt>preauth</tt> keyword and option were changed
back to <tt>auth</tt>. The <tt>preauth</tt> synonym will still be
supported through a few more point releases.</p>

<h3>If your file predates 5.6.5</h3>

<p>The <tt>imap-gss</tt>, <tt>imap-k4</tt>, and <tt>imap-login</tt>
protocol types are gone. This is a result of a major re-factoring
of the authentication machinery; fetchmail can now use Kerberos V4
and GSSAPI not just with IMAP but with POP3 servers that have
RFC1734 support for the AUTH command.</p>

<p>When trying to identify you to an IMAP or POP mailserver,
fetchmail now first tries methods that don't require a password
(GSSAPI, KERBEROS_IV); then it looks for methods that mask your
password (CRAM-MD5, X-OTP); and only if it the server doesn't
support any of those will it ship your password en clair.</p>

<p>Setting the <tt>preauth</tt> option to any value other than
'password' will prevent from looking for a password in your
<tt>.netrc</tt> file or querying for it at startup time.</p>

<h3>If your file predates 5.1.0</h3>

<p>In 5.1.0, the <tt>auth</tt> keyword and option were changed to
<tt>preauth</tt>.</p>

<h3>If your file predates 4.5.5</h3>

<p>If the <code>dns</code> option is on (the default), you may need
to make sure that any hostname you specify (for mail hosts or for
an SMTP target) is a canonical fully-qualified hostname). In order
to avoid DNS overhead and complications, fetchmail no longer tries
to derive the fetchmail client machine's canonical DNS name at
startup.</p>

<h3>If your file predates 4.0.6:</h3>

<p>Just after the '<code>via</code>' option was introduced, I
realized that the interactions between the '<code>via</code>',
'<code>aka</code>', and '<code>localdomains</code>' options were
out of control. Their behavior had become complex and confusing, so
much so that I was no longer sure I understood it myself. Users
were being unpleasantly surprised.</p>

<p>Rather than add more options or crock the code, I re-thought it.
The redesign simplified the code and made the options more
orthogonal, but may have broken some complex multidrop
configurations.</p>

<p>Any multidrop configurations that depended on the name just
after the '<code>poll</code>' or '<code>skip</code>' keyword being
still interpreted as a DNS name for address-matching purposes, even
in the presence of a '<code>via</code>' option, will break.</p>

<p>It is theoretically possible that other unusual configurations
(such as those using a non-FQDN poll name to generate Kerberos IV
tickets) might also break; the old behavior was sufficiently murky
that we can't be sure. If you think this has happened to you,
contact the maintainer.</p>

<h3>If your file predates 3.9.5:</h3>

<p>The '<code>remote</code>' keyword has been changed to
'<code>folder</code>'. If you try to use the old keyword, the
parser will utter a warning.</p>

<h3>If your file predates 3.9:</h3>

<p>It could be because you're using a .fetchmailrc that's written
in the old popclient syntax without an explicit
'<code>username</code>' keyword leading the first user entry
attached to a server entry.</p>

<p>This error can be triggered by having a user option such as
'<code>keep</code>' or '<code>fetchall</code>' before the first
explicit username. For example, if you write</p>

<pre>
poll openmail protocol pop3
    keep user "Hal DeVore" there is hdevore here
</pre>

<p>the '<code>keep</code>' option will generate an entire user
entry with the default username (the name of fetchmail's invoking
user).</p>

<p>The popclient compatibility syntax was removed in 4.0. It
complicated the configuration file grammar and confused users.</p>

<h3>If your file predates 2.8:</h3>

<p>The '<code>interface</code>', '<code>monitor</code>' and
'<code>batchlimit</code>' options changed after 2.8.</p>

<p>They used to be global options with '<code>set</code>' syntax
like the batchlimit and logfile options. Now they're per-server
options, like '<code>protocol</code>'.</p>

<p>If you had something like</p>

<pre>
    set interface = "sl0/10.0.2.15"
</pre>

<p>in your .fetchmailrc file, simply delete that line and insert
'interface sl0/10.0.2.15' in the server options part of your
'defaults' declaration.</p>

<p>Do similarly for any '<code>monitor</code>' or
'<code>batchlimit</code>' options.</p>

<h2><a id="F2" name="F2"><strike>F2. The .fetchmailrc parser won't accept
my all-numeric user name.</strike></a></h2>

<p><i>This referred to an older fetchmail 5.x version. Upgrade.</i></p>

<h2><a id="F3" name="F3"><strike>F3. The .fetchmailrc parser won't accept
my host or username beginning with 'no'.</strike></a></h2>

<p><i>This referred to an older fetchmail 5.x version. Upgrade.</i></p>

<h2><a id="F4" name="F4">F4. I'm getting a 'parse error' message I
don't understand.</a></h2>

<p>The most common cause of mysterious parse errors is putting a
server option after a user option. Check the manual page; you'll
probably find that by moving one or more options closer to the
'poll' keyword you can eliminate the problem.</p>

<p>Yes, I know these ordering restrictions are hard to understand.
Unfortunately, they're necessary in order to allow the 'defaults'
feature to work.</p>

<hr/>
<h1>Configuration questions</h1>
<h2><a id="C1" name="C1">C1. Why do I need a .fetchmailrc when
running as root on my own machine?</a></h2>

<p>Ian T. Zimmerman &lt;itz@rahul.net&gt; asked:</p>

<p>On the machine where I'm the only real user, I run fetchmail as
root from a cron job, like this:</p>

<pre>
    fetchmail -u "itz" -p POP3 -s bolero.rahul.net
</pre>

<p>This used to work as is (with no .fetchmailrc file in root's
home directory) with the last version I had (1.7 or 1.8, I don't
remember). But with 2.0, it RECPs all mail to the local root user,
unless I create a .fetchmailrc in root's home directory
containing:</p>

<pre>
     skip bolero.rahul.net proto POP3
          user itz is itz
</pre>

<p>It won't work if the second line is just "<code>user
itz</code>". This is silly.</p>

<p>It seems fetchmail decides to RECP the 'default local user'
(i.e. the uid running fetchmail) unless there are local aliases,
and the 'default' aliases (itz-&gt;itz) don't count. They
should.</p>

<p>Answer:</p>

<p>No they shouldn't. I thought about this for a while, and I don't
much like the conclusion I reached, but it's unavoidable. The
problem is that fetchmail has no way to know, in general, that a
local user 'itz' actually exists.</p>

<p>"Ah!" you say, "Why doesn't it check the password file to see if
the remote name matches a local one?" Well, there are two
reasons.</p>

<p>One: it's not always possible. Suppose you have an SMTP host
declared that's not the machine fetchmail is running on? You
lose.</p>

<p>Two: How do you know server itz and SMTP-host itz are the same
person? They might not be, and fetchmail shouldn't assume they are
unless local-itz can explicitly produce credentials to prove it
(that is, the server-itz password in local-itz's .fetchmailrc
file.).</p>

<p>Once you start running down possible failure modes and thinking
about ways to tinker with the mapping rules, you'll quickly find
that all the alternatives to the present default are worse or
unacceptably more complicated or both.</p>

<h2><a id="C2" name="C2">C2. How can I arrange for a fetchmail
daemon to get killed when I log out?</a></h2>

<p>The easiest way to dispatch fetchmail on logout (which will work
reliably only if you have just one login going at any time) is to
arrange for the command 'fetchmail -q' to be called on logout.
Under bash, you can arrange this by putting 'fetchmail -q' in the
file '~/.bash_logout'. Most csh variants execute '~/.logout' on
logout. For other shells, consult your shell manual page.</p>

<p>Automatic startup/shutdown of fetchmail is a little harder to
arrange if you may have multiple login sessions going. In the
contrib subdirectory of the fetchmail distribution there is some
shell code you can add to your .bash_login and .bash_logout
profiles that will accomplish this. Thank James Laferriere
&lt;babydr@nwrain.net&gt; for it.</p>

<p>Some people start up and shut down fetchmail using the ppp-up
and ppp-down scripts of pppd.</p>

<h2><a id="C3" name="C3">C3. How do I know what interface and
address to use with --interface?</a></h2>

<p>This depends a lot on your local networking configuration (and
right now you can't use it at all except under Linux and the newer
BSDs). However, here are some important rules of thumb that can
help. If they don't work, ask your local sysop or your Internet
provider.</p>

<p>First, you may not need to use --interface at all. If your
machine only ever does SLIP or PPP to one provider, it's almost
certainly by a point to point modem connection to your provider's
local subnet that's pretty secure against snooping (unless someone
can tap your phone or the provider's local subnet!). Under these
circumstances, specifying an interface address is fairly
pointless.</p>

<p>What the option is really for is sites that use more than one
provider. Under these circumstances, typically one of your provider
IP addresses is your mailserver (reachable fairly securely via the
modem and provider's subnet) but the others might ship your packets
(including your password) over unknown portions of the general
Internet that could be vulnerable to snooping. What you'll use
--interface for is to make sure your password only goes over the
one secure link.</p>

<p>To determine the device:</p>

<ol>
<li>If you're using a SLIP link, the correct device is probably
sl0.</li>

<li>If you're using a PPP link, the correct device is probably
ppp0.</li>

<li>If you're using a direct connection over a local network such
as an ethernet, use the command 'netstat -r' to look at your
routing table. Try to match your mailserver name to a destination
entry; if you don't see it in the first column, use the 'default'
entry. The device name will be in the rightmost column.</li>
</ol>

<p>To determine the address and netmask:</p>

<ol>
<li>If you're talking to slirp, the correct address is probably
10.0.2.15, with no netmask specified. (It's possible to configure
slirp to present other addresses, but that's the default.)</li>

<li>If you have a static IP address, run 'ifconfig &lt;device&gt;',
where &lt;device&gt; is whichever one you've determined. Use the IP
address given after "inet addr:". That is the IP address for your
end of the link, and is what you need. You won't need to specify a
netmask.</li>

<li>If you have a dynamic IP address, your connection IP will vary
randomly over some given range (that is, some number of the least
significant bits change from connection to connection). You need to
declare an address with the variable bits zero and a complementary
netmask that sets the range.</li>
</ol>

<p>To illustrate the rule for dynamic IP addresses, let's suppose
you're hooked up via SLIP and your IP provider tells you that the
dynamic address pool is 255 addresses ranging from 205.164.136.1 to
205.164.136.255. Then</p>

<pre>
    interface "sl0/205.164.136.0/255.255.255.0"
</pre>

<p>would work. To range over any value of the last two octets
(65536 addresses) you would use</p>

<pre>
    interface "sl0/205.164.0.0/255.255.0.0"
</pre>

<h2><a id="C4" name="C4">C4. How can I set up support for
sendmail's anti-spam features?</a></h2>

<p>This answer covers versions of sendmail from 8.9.3-20 (the
version installed in Red Hat 6.2) upwards. If you have an older
version, upgrade to sendmail 8.9.</p>

<p>Stock sendmails can now do anti-spam exclusions based on a
database of filter rules. The human-readable form of the database
is at <tt>/etc/mail/access</tt>. The database itself is at
<tt>/etc/mail/access.db</tt>.</p>

<p>The table itself uses email addresses, domain names, and network
numbers as keys. For example,</p>

<pre>
spammer@aol.com         REJECT
cyberspammer.com        REJECT
192.168.212             REJECT
</pre>

<p>would refuse mail from spammer@aol.com, any user from
cyberspammer.com (or any host within the cyberspammer.com domain),
and any host on the 192.168.212.* network. (This feature can be
used to do other things as well; see the sendmail
documentation for details)</p>

<p>To actually set up the database, run</p>

<pre>
makemap hash deny &lt;deny
</pre>

<p>To test, send a message to your mailing address from that host
and then pop off the message with fetchmail, using the -v argument.
You can monitor the SMTP transaction, and when the FROM address is
parsed, if sendmail sees that it is an address in spamlist,
fetchmail will flush and delete it.</p>

<p>Under no circumstances put your <strong>mailhost</strong> or
<strong>any host you accept mail from</strong> using fetchmail into
your reject file. You <strong>will</strong> lose mail if you do
this!!!</p>

<h2><a id="C5" name="C5">C5. How can I poll some of my mailboxes
more/less often than others?</a></h2>

<p>Use the <cite>interval</cite> keyword on the ones that should be
checked less often. For example, if you do a poll every 5 minutes,
and want to poll some mailboxes every 5 minutes and some every 30
minutes, use something like this:</p>

<pre>
poll mainsite.example.com  proto pop3 user ....
poll secondary.example.com proto pop3 interval 6 user ...
</pre>

<p>Then secondary.example.com will be polled every 6th time that
mainsite.example.com is polled, which with a polling interval of
every 5 minutes means that secondary.example.com will be polled
every 30 minutes.</p>

<h2><a id="C6" name="C6">C6. Fetchmail works OK started up manually,
but not from an init script.</a></h2>

<p>Often, startup scripts have a different environment than an
interactive login shell. For instance, $HOME might point to "/root"
when you are logged in as root, but it might be either unset, or
set to "/" when the startup scripts are running. That means
fetchmail at startup can't find the .fetchmailrc.</p>

<p>Pick a location (such as /etc/fetchmailrc) and use fetchmail's
-f option to point fetchmail at it. That should solve the
problem.</p>

<h2><a id="C7" name="C7">C7. How can I forward mail to another
host?</a></h2>

<p>To forward mail to a host other than the one you are running
fetchmail on, use the <code>smtphost</code> or
<code>smtpname</code> option. See the manual page for details.</p>

<h2><a id="C8" name="C8">C8. Why is "NOMAIL" an error?/I frequently get messages
from cron!</a></h2>

<p>Some users want to write scripts that take action only if mail
could/could not be retrieved, thus fetchmail reports if it has retrieved
messages or not.</p>

<p>If you do not want "no mail" to be an error condition (for instance,
for cron jobs), use a POSIX-compliant shell and add this to the end of
the fetchmail command line, it will change an exit code of 1 to 0 and
others to 1:</p>
<pre>
|| [ $? -eq 1 ]
</pre>

<p>If you want to map more than one code to 0, you cannot cascade multiple
<strong>|| [ $? -eq N ]</strong>, but you must instead use the
<strong>-o</strong> operator inside the brackets, (see the test(1)
manpage for details), such as:</p>

<p>A full cron line might then look like this:</p>

<pre>
*/15 * * * * fetchmail -s || [ $? -eq 1 ]
</pre>

<hr/>
<h1>How to make fetchmail play nice with various MTAs</h1>
<h2><a id="T1" name="T1">T1. How can I use fetchmail with
sendmail?</a></h2>

<p>For most sendmails, no special configuration is required. Eric
Allman tells me that if <code>FEATURE(always_add_domain)</code> is
included in sendmail's configuration, you can leave the
<code>rewrite</code> option off.</p>

<p>If your sendmail complains "sendmail does not relay", make
sure your sendmail.cf file says <code>Cwlocalhost</code> so that
sendmail recognizes 'localhost' as a name of its host.</p>

<p>If you're mailing from another machine on your local network,
also ensure that its IP address is listed in ip_allow or name in
name_allow (usually in /etc/mail/)</p>

<p>If you find that your sendmail doesn't like the address
'FETCHMAIL-DAEMON@localhost' (which is used in the bouncemail that
fetchmail generates), you may have to set
<code>FEATURE(accept_unqualified_senders)</code>.</p>

<p>G&uuml;nther Leber reports that Digital Unix sendmails won't
work with fetchmail. The symptom is an error message "<code>553
Local configuration error, hostname not recognized as
local</code>". The problem is that fetchmail normally feeds
sendmail with the client machine's host address in the MAIL FROM
line. These sendmails think this means they're seeing the result of
a mail loop and suppress the mail. You may be able to work around
this by running in <code>--invisible</code> mode.</p>

<p>If you want to support multidrop mode, and you can get access to
your mailserver's sendmail.cf file, it's a good idea to add this
rule:</p>

<pre>
H?l?Delivered-To: $h
</pre>

<p>This will cause the mailserver's sendmail to reliably write the
appropriate envelope address into each message before fetchmail
sees it, and tell fetchmail which header it is.&#160; With this
change, multidrop mode should work reliably even when the Received
header omits the envelope address (which will typically be the case
when the message has multiple recipients).&#160; However it will
still not distinguish the recipients, your only advantage is that
no bounce will be sent if a message is BCC addressed to multiple
users at your site.&#160; To fix even that problem, you might want
to try the following hack, which is however untested and quite
experimental:</p>

<pre>
H?J?Delivered-To: $u

Mmdrop, P=/usr/bin/procmail, F=lsDFMqSPfhnu9J,
    S=EnvFromSMTP/HdrFromSMTP, R=EnvToSMTP/HdrToSMTP,
    T=DNS/RFC822/X-Unix,
    A=procmail -Y -a $u -d $h
</pre>

<p>For both hacks, you have to declare '<code>envelope
"Delivered-To:"</code>' on the fetchmail side, to put the virtual
domain (e.g. 'domain.com') with RELAY permission into your access
file and to add a line reading '<code>domain.com
local:local-pop-user</code>' for the first and '<code>domain.com
mdrop:local-pop-user</code>' for the second hack to your
mailertable.</p>

<p>You will notice that if the mail already has a Delivered-To
header, sendmail will not add another.&#160; Further, editing
sendmail.cf directly is not very comfortable.&#160; Solutions for
both problems can be found in Peter 'Rattacresh' Backes' 'hybrid'
patch against sendmail.&#160; Have a look at it, you can find it in
the contrib subdirectory.</p>

<p>Feel free to try Martijn Lievaart's detailed recipe in the
contrib subdirectory of the fetchmail source distribution, it
attempts to realize multidrop mailboxes with an external
script.</p>

<p>If for some reason you are invoking sendmail via the
<tt>mda</tt> option (rather than delivering to port 25 via smtp),
don't forget to include the -i switch. Otherwise you will
occasionally get mysterious delivery failures with a SIGPIPE as the
sendmail instance dies. The problem is messages with a single dot
at start of a text line.</p>

<h2><a id="T2" name="T2">T2. How can I use fetchmail with
qmail?</a></h2>

<h3>qmail as your local SMTP server</h3>

<p>Don't! Avoid qmail and netqmail, they are broken and unmaintained.</p>

<p>Turn on the <code>forcecr</code> option; qmail's listener mode
doesn't like header or message lines terminated with bare
linefeeds.<br/>
(This information contributed by Robert de Bath
&lt;robert@mayday.cix.co.uk&gt;.)</p>

<h3>qmail as your ISP's POP3 server</h3>

<p>Note that qmail's POP3 server, as of version 1.03 and netqmail 1.05,
miscalculates the message sizes, so you may see size-related fetchmail
warnings.</p>

<p>If a mailhost is using the qmail package, then it is usually possible
to set up one fetchmail link to reliably collect the mail for an entire
domain.</p>

<p>One of the basic features of qmail is the 'Delivered-To:'
message header. Whenever qmail delivers a message to a local
mailbox it puts the username and hostname of the envelope recipient
on this line. One major reason for this is to prevent mail
loops, the other is to transport envelope information which is essential
for multidrop (domain-in-a-mailbox) schemes.</p>

<p>To set up qmail to batch mail for a disconnected site, the
ISP-mailhost will have normally put that site in its 'virtualhosts'
control file so it will add a prefix to all mail addresses for this
site. This results in mail sent to
'username@userhost.userdom.example.com' having a 'Delivered-To:' line
of the form:</p>

<pre>
       Delivered-To: mbox-userstr-username@userhost.userdom.example.com
</pre>

<p>A single host maildrop will be slightly simpler:</p>

<pre>
       Delivered-To: mbox-userstr-username@userhost.example.com
</pre>

<p>The ISP can make the 'mbox-userstr-' prefix anything they choose
but a string matching the user host name is likely.</p>

<ol>
    <li>Ensure the option '<code>envelope "Delivered-To"</code>' is in the fetchmail
config file.</li>

<li>Ensure the option '<code>qvirtual "mbox-userstr-"</code>' is
in the fetchmail config file, in order to remove this prefix from the
username. (added by Luca Olivetti)</li>

<li>Ensure you have a <code>localdomains</code> option containing
'<code>userdom.example.com</code>' or '<code>userhost.userdom.example.com</code>'
respectively.</li>
</ol>

<h2><a id="T3" name="T3">T3. How can I use fetchmail with
exim?</a></h2>

<p>If you have <code>rewrite</code> on:</p>

<p>There is an RFC1123 requirement that MAIL FROM and RCPT TO
addresses you pass to it have to be canonical (e.g. with a fully
qualified hostname part). Therefore fetchmail tries to pass fully
qualified RCPT TO addresses. But exim does not by default accept
'localhost' as a fully qualified domain. This can be fixed.</p>

<p>In exim.conf, add 'localhost' to your local_domains declaration
if it's not already present. For example, the author's site at
thyrsus.com would have a line reading:</p>

<pre>
       local_domains = thyrsus.com:localhost
</pre>

<p>If you have <code>rewrite</code> off:</p>

<p>MAIL FROM is a potential problem if the MTAs upstream from your
fetchmail don't necessarily pass canonicalized From and Return-Path
addresses, and fetchmail's <code>rewrite</code> option is off. The
specific case where this has come up involves bounce messages
generated by sendmail on your mailer host, which have the
(un-canonicalized) origin address MAILER-DAEMON.</p>

<p>The right way to fix this is to enable the <code>rewrite</code>
option and have fetchmail canonicalize From and Return-Path
addresses with the mailserver hostname before exim sees them. This
option is enabled by default, so it won't be off unless you turned
it off.</p>

<p>If you must run with <code>rewrite</code> off, there is a switch
in exim's configuration files that allows it to accept domainless
MAIL FROM addresses; you will have to flip it by putting the
line</p>

<pre>
        sender_unqualified_hosts = localhost
</pre>

<p>in the main section of the exim configuration file. Note that
this will result in such messages having an incorrect domain name
attached to their return address (your SMTP listener's hostname
rather than that of the remote mail server).</p>

<h2><a id="T4" name="T4">T4. How can I use fetchmail with
smail?</a></h2>

<p>Smail 3.2 is very nearly plug-compatible with sendmail, and may
work fine out of the box.</p>

<p>We have one report that when processing multiple messages from a
single fetchmail session, smail sometimes delivers them in an order
other than received-date order. This can be annoying because it
scrambles conversational threads. This is not fetchmail's problem,
it is an smail 'feature' and has been reported to the maintainers
as a bug.</p>

<p>Very recent smail versions require an
<code>-smtp_hello_verify</code> option in the smail config file.
This overrides smail's check to see that the HELO address is
actually that of the client machine, which is never going to be the
case when fetchmail is in the picture. According to RFC1123 an SMTP
listener <em>must</em> allow this mismatch, so smail's new behavior
(introduced sometime between 3.2.0.90 and 3.2.0.95) is a bug.</p>

<p>You may also need to say
<code>-smtp_hello_broken_allow=127.0.0.1</code> in order for smail
to accept the "localhost" that fetchmail normally appends to
recipient addresses.</p>

<h2><a id="T5" name="T5">T5. How can I use fetchmail with SCO's
MMDF?</a></h2>

<p>MMDF itself is difficult to configure, but it turns out that
connecting fetchmail to MMDF's SMTP channel isn't that hard. You
can read an <a
href="https://aplawrence.com/Unixart/uucptofetch.html">MMDF
recipe</a> that describes replacing a UUCP link with fetchmail
feeding MMDF.</p>

<h2><a id="T6" name="T6">T6. How can I use fetchmail with Lotus
Notes?</a></h2>

<p>The Lotus Notes SMTP gateway tries to deduce when it should
convert \n to \r\n, but its rules are not the intuitive and
correct-for-RFC822 ones. Use 'forcecr'.</p>

<h2><a id="T7" name="T7">T7. How can I use fetchmail with Courier
IMAP?</a></h2>

<p>The courier mta doesn't like RCPT addresses that look like
<code>someone@localhost</code>. Work around this with an
<code>smtphost</code> or <code>smtpaddress</code>.</p>

<h2><a name="T8">T8. How can I use fetchmail with vbmailshield?</a></h2>

<p>vbmailshield's SMTP interpreter is broken.  It doesn't understand RSET.</p>

<p>As a workaround, you can set batchlimit to 1 so RSET is never used.</p>

<hr/>
<h1>How to make fetchmail work with various servers</h1>
<h2><a id="S1" name="S1"><strike>S1. How can I use fetchmail with
	qpopper?</strike></a></h2>

<p><em>The information that used to be here was obsolete and dropped.</em></p>

<h2><a id="S2" name="S2">S2. How can I use fetchmail with Microsoft
Exchange?</a></h2>

<p>It's been reliably reported that Exchange 2000's POP3 support is
so broken that it's unusable. One symptom is that messages without
a terminating newline get the POP3 message termination dot emitted
-- you guessed it -- right after the last character of the message,
with no terminating newline added. This will hang fetchmail or any
other RFC-compliant server. IMAP is alleged to work OK, though.</p>

<p>Older versions of Exchange are semi-usable.  They randomly drop
attachments on the floor, though.  Microsoft acknowledges this
as a known bug and apparently has no plans to fix it.</p>

<p>Fetchmail using IMAP usually supports the proprietary NTLM mode used
with Microsoft Exchange servers. "Usually" here means that it fails on some
servers for reasons that we haven't been able to debug yet, perhaps it's
related to the NTLM domain.</p>

<p>To enable this NTLM mode, configure fetchmail with
the --enable-NTLM option and recompile it. Specify a user option
value that looks like 'user@domain': the part to the left of the @
will be passed as the username and the part to the right as the
NTLM domain.</p>

<p>Microsoft Exchange violates the POP3 and IMAP RFCs. Its LIST command
does not reveal the real sizes of mail in the pop mailbox, but the
sizes of the compressed versions in the exchange mail database
(thanks to Arjan De Vet and Guido Van Rooij for alerting us to this
problem).</p>

<p>Fetchmail works with Microsoft Exchange, despite this brain damage.
Two features are compromised. One is that the --limit option will not
work right (it will check against compressed and not actual sizes).
The other is that a too-small SIZE argument may be passed to your
ESMTP listener, assuming you're using one (this should not be a
problem unless the actual size of the message is above the
listener's configured length limit).</p>

<p>ESR learned that there's supposed to be a
registry bit that can fix this breakage:</p>

<pre>
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MsExchangeIs\Parameters
System\Pop3 Compatibility
</pre>

<p>This is a bitmask that controls the variations from the standard
protocol. The bits defined are:</p>

<dd>Report exact message sizes for the LIST command</dd>

<dd>Allow arbitrary linear whitespace between commands and
arguments</dd>

<dd>Enable the LAST command</dd>

<dd>Allow an empty PASS command (needed for users with blank
passwords, but illegal in the protocol)</dd>

<dd>Relax the length restrictions for arguments to commands
(protocol requires 40, but some user names may be longer than
that).</dd>

<dd>Allow spaces in the argument to the USER command.</dd>
</dl>

<p>There's another one that may be useful to know about:</p>

<pre>
KEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MsExchangeIs\Parameters
System\Pop3 Performance
</pre>

<dd>Render messages to a temporary stream instead of sending
directly from the database (should always be on)</dd>

<dt>0x00000002: Flag unrenderable messages (instead of just failing
commands) (should only be on if you are seeing the problems
reported in KB Q168109)</dt>

<dd>Return from the QUIT command before all messages have been
deleted.</dd>
</dl>

<p>The Microsoft employee who revealed this information to ESR
admitted that he couldn't find it anywhere in their public
knowledge base.</p>

<p>Another specific problem we have seen with Exchange servers has
as its symptom a response to LOGIN that says "NO Ambiguous Alias".
Grant Edwards writes:</p>

<blockquote><p>This means that Exchange Server is too [...] stupid to
figure out which mailbox belongs to you. Instead of actually
keeping track of which inbox belongs to which user, it uses some
half-witted, guess-o-matic heuristic to try to guess your mailbox
name from your username.</p>

<p>In your case it doesn't work because your username maps to more
than one mailbox. For some people it doesn't work because their
username maps to zero mailboxes.</p>

<p>You've got several options:</p>

<ul>
<li>Get your administrator to configure the server so that
usernames and mailbox names are the same.</li>

<li>Get your administrator to add an alias that maps your username
explicitly to your mailbox name.</li>
</ul>
</blockquote>

<p>But, the best option involves finding a server that runs better
software.</p>

<h2><a id="S3" name="S3">S3. How can I use fetchmail with HP
OpenMail?</a></h2>

<p>No special configuration is required, but OpenMail versions
prior to 6.0 have an annoying bug similar to the big one in <a
href="#S2">Microsoft Exchange</a>. The message sizes it gives in
the LIST are rounded to the nearest 1024 bytes. It also has a nasty
habit of discarding headers it doesn't recognize, such as X- and
Resent- headers.</p>
<p>OpenMail's project manager claims these bugs have been fixed in
6.0.</p>

<p>We've had a more recent report (December 2001) that the TOP
command fails, returning only one line regardless of its argument,
on something identifying itself as "OpenMail POP3 interface".</p>

<h2><a id="S4" name="S4">S4. How can I use fetchmail with Novell GroupWise?</a></h2>

<p>The Novell GroupWise IMAP server is (according to the designer of
IMAP) unusably broken. Among other things, it doesn't include a required
content length in its BODY[TEXT] response.</p>

<p>Fetchmail works around this problem to some extent, but no guarantees.</p>

<h2><a id="S5" name="S5">S5. How can I use fetchmail with
InterChange?</a></h2>

<p>You can't. At least not if you want to be able to see
attachments. InterChange has a bug similar to the MailMax server (<a
    href="#S6">see below</a>):
it reports the message length with attachments but doesn't download
them on TOP or RETR.</p>

<p>On Jan 9 2001, the people at InfiniteMail sent ESR mail informing
him that their new 3.61.08 release of InterChange fixed this
problem.</p>

<h2><a id="S6" name="S6">S6. How can I use fetchmail with MailMax?</a></h2>

<p>You can't. At least not if you want to be able to see
attachments. MailMax has a bug; it reports the message length with
attachments but doesn't download them on TOP or RETR.</p>

<p>Also, we're told that TOP sometimes fails to retrieve the entire
message even when enough lines have been specified. The MailMax
developers have acknowledged this bug as of 4 May 2000, but there
is no fix yet. If you must use this server, force RETR with the
<tt>fetchall</tt> option.</p>

<h2><a id="S7" name="S7">S7. How can I use fetchmail with FTGate?</a></h2>

<p>The FTGate V2 server (and possibly older versions as well) has a
weird bug. It answers OK twice to a TOP request! Use the
<code>fetchall</code> option to force use of RETR and work around
this bug.</p>

<hr/>
<h1>How to fetchmail work with specific ISPs</h1>
<h2><a id="I1" name="I1">I1. How can I use fetchmail with CompuServe RPA?</a></h2>

<p>First, make sure your fetchmail has the RPA support compiled in.
Stock fetchmail binaries (such as you might get from an RPM) don't.
You can check this by looking at the output of <code>fetchmail
-V</code>; if you see the string "+RPA" after the version ID you're
good to go, otherwise you'll have to build your own from sources
(see the INSTALL file in the source distribution for
directions).</p>

<p>Give your CompuServe pass-phrase in lower case as your password.
Add '@compuserve.com' to your user ID so that it looks like 'user
&lt;UserID&gt;@compuserve.com', where &lt;UserID&gt; can be either
your numerical userID or your E-mail nickname. An RPA-enabled
fetchmail will automatically check for csi.com in the POP server's
greeting line. If that's found, and your user ID ends with
'@compuserve.com', it will query the server to see if it is
RPA-capable, and if so do an RPA transaction rather than a
plain-text password handshake.</p>

<p><strong>Warning:</strong> the debug (-v -v) output of fetchmail
will show your pass-phrase in Unicode!</p>

<p>These two .fetchmailrc entries show the difference between an
RPA and non-RPA configuration:</p>

<pre>
# This version will use RPA
poll csi.com via "pop.site1.csi.com" with proto POP3 and options no dns
    user "CSERVE_USER@compuserve.com" there with password "CSERVE_PASSWORD"
        is LOCAL_USER here options fetchall stripcr

# This version will not use RPA
poll non-rpa.csi.com via "pop.site1.csi.com" with proto POP3 and options no dns
    user "CSERVE_USER" there with password "CSERVE_POP3_PASSWORD"
       is LOCAL_USER here options fetchall stripcr
</pre>

<h2><a id="I2" name="I2">I2. How can I use fetchmail with Demon
Internet's SDPS?</a></h2>

<h3>Single-drop mode</h3>

<p>You can get fetchmail to download the email for just one user
from Demon Internet's POP3 server by giving it a username
consisting of your Demon user name followed by your account name,
with an at-sign between them.</p>

<p>For example, to download email for the user
&lt;philh@vision25.demon.co.uk&gt;, you could use the following
.fetchmailrc file:</p>

<pre>
set postmaster "philh"
poll pop3.demon.co.uk with protocol POP3:
    user "philh@vision25" is philh
</pre>

<h3>Multi-drop mode</h3>

<p>Demon Internet's SDPS service is an implementation of POP3. All
messages have a Received: header added when they enter the
maildrop, like this:</p>

<pre>
   Received: from punt-1.mail.demon.net by mailstore for fred@xyz.demon.co.uk
             id 899963657:10:27896:0; Thu, 09 Jul 98 05:54:17 GMT
</pre>

<p>To enable multi-drop mode you need to tell fetchmail that
'mailstore' is the name of the host which accepted the mail, and
let it know the hostname part(s) of your E-mail address. The
following example assumes that your hostname is xyz.demon.co.uk,
and that you have also bought "mail forwarding" for the domain
my-company.co.uk (in which case your MTA must also be configured to
accept mail sent to user@my-company.co.uk)</p>

<pre>
     poll pop3.demon.co.uk proto pop3 aka mailstore no dns:
       localdomains xyz.demon.co.uk my-company.co.uk
       user xyz is *
</pre>

<p>Note that Demon may delete mail on the server which is more than
30 days old; see their <a
href="http://help.demon.net/help-articles/troubleshooting-and-faqs/30-day-mail-deletion-information/">POP3
page</a> for details.</p>

<h3>The SDPS extension</h3>

<p>There's a different way to do multidrop. It's not necessary on
Demon Internet, since fetchmail can parse Received addresses, but
the person who implemented this didn't know that. It may be useful
if Demon Internet ever changes mail transports.</p>

<p>SDPS includes a non-standard extension for retrieving the
envelope of a message (*ENV), which fetchmail optionally supports
if compiled with the --enable-SDPS option. If you have it, the
first line of the fetchmail -V response will include the string
"+SDPS".</p>

<p>Once you have SDPS compiled in, fetchmail in POP3 mode will
automatically detect when it's talking to a Demon Internet host in
multidrop mode, and use the *ENV extension to get an envelope To
address.</p>

<p>The autodetection works by looking at the hostname in the POP3
greeting line; if you're accessing Demon Internet through a proxy
it may fail. To force SDPS mode, pick "sdps" as your protocol.</p>

<h2><a id="I3" name="I3">I3. How can I use fetchmail with usa.net's
servers?</a></h2>

<p>Enable '<code>fetchall</code>'. A user reports that the 2.2
version of USA.NET's POP server reports that you must use the
'<code>fetchall</code>' option to make sure that all of the mail is
retrieved, otherwise some may be left on the server. This is almost
certainly a server bug.</p>

<p>The usa.net servers (at least in their 2.2 version, June 1998)
don't handle the TOP command properly, either. Regardless of the
argument you give it, they retrieve only about 10 lines of the
message. Fetchmail normally uses TOP for message retrieval in order
to avoid marking messages seen, but '<code>fetchall</code>' forces
it to use RETR instead.</p>

<p>Also, we're told USA.NET adds a ton of hops to your messages.
You may need to raise the MaxHopCount parameter in your sendmail.cf
to avoid having fetched mail rejected.</p>

<h2><a id="I4" name="I4">I4. How can I use fetchmail with geocities
POP3 servers?</a></h2>

<p>Nathan Cutler reports that the the mail.geocities.com POP3
servers fail to include the first Received line of the message in
the send to fetchmail. This can solve problems if your MUA
interprets Received continuations as body lines and doesn't parse
any of the following headers.</p>

<p>Workaround is to use "mda" keyword or "--mda" switch:</p>

<pre>
mda "sed -e '1s/^\t/Received: /' | formail | /usr/bin/procmail -d &lt;user&gt;"
</pre>

<p>Replace \t with exactly one tabulation character.</p>

<p>You should also consider using "fetchall" option because
Geocities' servers sometimes think that the first 45 messages have
already been read.</p>

<h2><a id="I5" name="I5"><strike>I5. How can I use fetchmail with Hotmail or Lycos Webmail?</strike></a></h2>

<p><i>It appears that both services offer POP3 or IMAP access these days.</i></p>
<p>Other than that, it might be possible to use
the <a
href='https://sourceforge.net/projects/hotwayd/'>HotWayDaemon</a>
daemon. You don't even need to install hotwayd as a daemon in
<samp>inetd.conf</samp> but can use it as a plugin. Your
configuration should look like this:</p>

<pre>
poll localhost protocol pop3 tracepolls
   plugin "/usr/local/sbin/hotwayd -l 0 -p yourproxy:yourproxyport"
   username "youremail@hotmail.com" password "yourpassword"
   fetchall
</pre>

<p>As a second option you may consider using <a
href="https://sourceforge.net/projects/getlive/">GetLive</a>, a successor to the discontinued Gotmail.</p>

<h2><a id="I6" name="I6">I6. How can I use fetchmail with MSN?</a></h2>

<p>See <a href="#I5">I5</a> above.</p>

<h2><a id="I7" name="I7">I7. How can I use fetchmail with SpryNet?</a></h2>

<p><i>SpryNet is no more.</i></p>

<h2><a id="I8" name="I8">I8. How can I use fetchmail with comcast.net or
	other Maillennium servers?</a></h2>

<p>Stock fetchmail will work with a
Maillennium&nbsp;POP3/PROXY&nbsp;server... <em>but</em> this server will
truncate "TOP" responses after 64&nbsp;-&nbsp;82 kB (we have varying reports),
in violation of Internet Standard #53 aka. RFC-1939 (POP3). Don't
mistake this for a fetchmail bug. (Reported July 2003.) Comcast
documented they haven't understood what this is about in <a
    href="https://www.mhonarc.org/archive/html/fetchmail-friends/2004-04/msg00054.html">two
    messages from April 2004.</a></p>

<p>Beginning with version 6.3.2, fetchmail will fall back to the RETR
command if the greeting string contains "Maillennium POP3/PROXY server",
and print a warning message. This means however that fetchmail has no
means to prevent the "seen" flag from being set on the server (Note that
officially, POP3 has no notion of seen tracking, but it works for some
sites.)</p>

<p>Workaround for older versions: use the <tt>fetchall</tt> option.</p>

<h2><a id="I9" name="I9">I9. How can I use fetchmail with GMail/Google Mail?</a></h2>

<p>Google has started pushing towards more complex authentication
schemes based on OAuth 2.0 that require clients and users
to jump through quite a few hoops, and use web browsers for signing in.
If this hinders access to your account through fetchmail, you may need to turn on access for "less secure apps" at <a
    href="https://myaccount.google.com/lesssecureapps">https://myaccount.google.com/lesssecureapps</a>.<br/>
It is disputable whether an application that does not include web
browsing capabilities or heavy-weight libraries is "less secure" as
Google claims.</p>

<p>Google's IMAP servers, as of April 2008, are broken and re-encode
MIME-encoded headers improperly and are not feature-complete yet. The
model how their servers organize mail also deviates in significant ways
from what the POP3 or IMAP protocol 'fathers' conceived. This means all
sorts of strange effects, for instance, your sent mail may show up in
the mail that fetchmail fetches. It's best to avoid fetching mail from
Google until they are using standards-compliant software.</p>

<p>If you still need to use Google's mail service, these links may help (valid as of 2011-04-13):</p>
<ul>
    <li><a href="http://mail.google.com/support/bin/topic.py?hl=en&amp;topic=12805">Other ways to access Gmail &gt; POP</a></li>
    <li><a href="http://mail.google.com/support/bin/topic.py?hl=en&amp;topic=12806">Other ways to access Gmail &gt; IMAP</a></li>
<li><a href="http://mail.google.com/support/bin/answer.py?hl=en&amp;answer=47948">Using POP on multiple clients or mobile devices</a></li>
<li><a href="http://mail.google.com/support/bin/answer.py?hl=en&amp;answer=13291">Some [POP3] mail was not downloaded</a></li>
<li><a href="http://mail.google.com/support/bin/answer.py?hl=en&amp;answer=78774">I'm having problems downloading [IMAP] mail</a></li>
</ul>

<hr/>
<h1>How to set up well-known security and authentication
methods</h1>
<h2><a id="K1" name="K1">K1. How can I use fetchmail with SOCKS?</a></h2>

<p>Giuseppe Guerini added a <kbd>--with-socks</kbd> compile-time option
that supports linking with socks library. If you specify the value of
this option as "yes", the configure script will try to find the Rconnect
library and set the makefile up to link it. You can also specify a
directory containing the Rconnect library.</p>

<p>Alan Schmitt has added a similar <kbd>--with-socks5</kbd> option that may
work better if you have a recent version of the SOCKS library.</p>

<p>In either case, fetchmail has no direct configuration hooks, but you
can specify which socks configuration file the library should read by
means of the <tt>SOCKS_CONF</tt> environment variable. In order to
bypass the SOCKS proxy altogether, you could run (adding your usual
options to the end of this line):</p>

<pre>env SOCKS_CONF=/dev/null fetchmail</pre>

<h2><a id="K2" name="K2">K2. How can I use fetchmail with IPv6 and
IPsec?</a></h2>

<p>To use fetchmail with IPv6, you need a system that supports
IPv6, the "Basic Socket Interface Extensions for IPv6" (RFC 2133).
</p>

<p>The NRL IPv6+IPsec software distribution can be obtained from:
<a
href="http://web.mit.edu/network/isakmp/">http://web.mit.edu/network/isakmp/</a></p>

<p>More information on using IPv6 with Linux can be obtained
from:</p>

<ul>
<li><a
href="http://www.bieringer.de/linux/IPv6/IPv6-HOWTO/IPv6-HOWTO.html">
http://www.bieringer.de/linux/IPv6/IPv6-HOWTO/IPv6-HOWTO.html</a></li>
</ul>

<h2><a id="K3" name="K3">K3. How can I get fetchmail to work with
ssh?</a></h2>

<p>Use the <tt>plugin</tt> option. This is dead simple with
IMAP:</p>

<pre>
    plugin "ssh %h /usr/sbin/imapd"
</pre>

<p>You may have to use a different absolute pathname, whatever the
location of imapd on your mailserver is. This option tells
fetchmail that instead of opening a connection on the server's port
143 and doing standard IMAP authentication, fetchmail should ssh to
the server and run imapd, using the more secure ssh authentication
(as well as getting ssh's end-to-end encryption). Most IMAP daemons
will detect that they've been called from the command line and
assume the connection is preauthenticated.</p>

<p>POP3 daemons aren't quite as smart. They won't know they are
preauthenticated in this mode, so you'll actually have to ship your
password. It will be under ssh encryption, though, so that
shouldn't be a problem.</p>

<h2><a id="K4" name="K4">K4. What do I have to do to use the
IMAP-GSS protocol?</a></h2>

<p>Fetchmail can use RFC1731 GSSAPI authorization to safely
identify you to your IMAP server, as long as you can share
Kerberos&nbsp;V credentials with your mail host and you have a GSSAPI-capable
IMAP server.</p>

<p>fetchmail does not compile in support for GSS by
default, since it requires libraries from a Kerberos V
distribution, such as <a href="http://web.mit.edu/Kerberos/">MIT
    Kerberos</a> or <a href="http://www.h5l.org/">Heimdal
    Kerberos</a>.</p>

<p>If you have these, compiling in GSS support is simple: add a
<code>--with-gssapi=[/path/to/krb5/root]</code> option to
configure. For instance, I have all of my Kerberos V libraries
installed under /usr/krb5 so I run <code>configure
--with-gssapi=/usr/krb5</code></p>

<p>Setting up Kerberos V authentication is beyond the scope of this
FAQ (you may find Jim Rome's paper <a
href="https://web.ornl.gov/~romeja/HowToKerb.html">How to Kerberize
your site</a> helpful), but you'll at least need to add a
credential for imap/[mailhost] to the keytab of the mail server
(IMAP doesn't just use the host key). Then you'll need to have your
credentials ready on your machine (cf. kinit).</p>

<p>After that things are very simple. Set your protocol to imap-gss
in your .fetchmailrc, and omit the password, since imap-gss doesn't
need one. You can specify a username if you want, but this is only
useful if your mailbox belongs to a username different from your
Kerberos principal.</p>

<p>Now you don't have to worry about your password appearing in
cleartext in your .fetchmailrc, or across the network.</p>

<h2><a id="K5" name="K5">K5. How can I use fetchmail with
SSL or TLS?</a></h2>

<p>You'll need to have the <a
href="https://www.openssl.org/">OpenSSL</a> libraries installed, and they
should at least be version 1.1.1.
Configure with --with-ssl (default since fetchmail v6.4.0). If you have the OpenSSL libraries
installed in commonly-used default locations, this will
suffice. If you have them installed in a non-default location,
you'll need to specify the OpenSSL installation directory as an argument
to --with-ssl after an equal sign.</p>

<p>Fetchmail binaries built this way support <code>ssl</code> and <code>tls</code>,
<code>sslkey</code>, and <code>sslcert</code> options that control
SSL encryption, and will automatically try to negotiate <code>starttls</code> or <code>stls</code>if the
server offers it. You will need to have an SSL/TLS-enabled mailserver to
use these options. See the manual page for details and some words
of care on the limited security provided.</p>

<p>If your open OpenSSL session dies with a message that complains
"PRNG not seeded", update or improve your operating system. This
means that the OpenSSL library on your machine has been unable to
locate a source of random bits from which to seed its random-number
generator; normally these come from the <tt>/dev/urandom</tt>, and
this message probably means your OS doesn't have that device.</p>

<p>An interactive program could seed the random number generator
from keystroke timings or some other form of user input. Because
fetchmail is primarily designed to run forever as a background
daemon, that option is not available in this case.</p>

<p>If you don't have the libraries installed, but do have the
OpenSSL utility toolkit, something like this may work (but will not
authenticate the server):</p>

<pre>
poll MYSERVER port 993 plugin "openssl s_client -connect %h:%p"
        protocol imap username MYUSERNAME password MYPASSWORD
</pre>

<p>You should note that SSL or TLS are only secure against a
"man-in-the-middle" attack if the client is able to verify that the
presented peer's public key is the correct one, and has not been substituted by an
attacker along the way. fetchmail can do this in one of two ways: by verifying the SSL
certificate, or by checking the fingerprint of the peer's public
key.</p>

<p>There are three parts to TLS certificate verification: checking that the
domain name in the certificate matches the hostname you asked to connect to;
checking that the certificate expiry date has not passed; and checking that
the certificate has been signed by a known Certificate Authority (CA). This
last step takes some preparation, as you need to install the root
certificates of all the CA's which you might come across.</p>

<p>The easiest way to do this is using the root CA keys supplied in the
OpenSSL distribution, which means you need to download and unpack the
source tarball from www.openssl.org. Once you have done that:</p>

<ol>
<li><code>mkdir /etc/ssl/certs</code></li>
<li>in the openssl-x.x.x/certs directory: <code>cp *.pem /etc/ssl/certs/</code></li>
<li>in the openssl-x.x.x/tools directory: edit c_rehash and set
<code>$dir="/etc/ssl"</code></li>
<li>run "perl c_rehash". This generates a number of symlinks within the
/etc/ssl/certs/ directory</li>
</ol>

<p>Now in .fetchmailrc, set option sslcertpath to point to this
directory:</p>

<pre>
poll pop3.example.com proto pop3 uidl no dns
  user foobar@example.com password xyzzy is foobar ssl sslcertpath /etc/ssl/certs
</pre>

<p>If the server certificate has not been signed by a known CA (e.g. it is a
self-signed certificate), then this certificate validation will always
fail.</p>

<p>Certificate verification is always attempted. If it fails, since v6.4.0,
by default the connection aborts (6.3 and older would carry on after printing
a warning, unless <code>--sslcertck</code> was in effect).

If your server doesn't have a valid certificate though (e.g. it
has a self-signed certificate) then it will never verify, and the only way
you can protect yourself is by checking the fingerprint. You should then contact
the operator and as for properly issued certificates.
</p>

<p>To check the peer fingerprint: first use fetchmail -v once to connect to
the host, at a time when you are pretty sure that there is no attack in
progress (e.g. you are not traversing any untrusted network to reach the
server). Make a note of the fingerprint shown. Now embed this in your
.fetchmailrc using the sslfingerprint option: e.g.</p>

<pre>
poll pop3.example.com proto pop3 uidl no dns
  user foobar@example.com password xyzzy is foobar
  ssl sslfingerprint "67:3E:02:94:D3:5B:C3:16:86:71:37:01:B1:3B:BC:E2"
</pre>

<p>When you next connect, the public key presented by the server will be
verified against the fingerprint given. If it's different, it may mean that
a man-in-the-middle attack is in progress - or it might just mean that the
server changed its key. It's up to you to determine which has happened.</p>

<h2><a id="K6" name="K6">K6. How can I tell fetchmail not to use TLS
	if the server advertises it? Why does fetchmail use STARTTLS, STLS, TLS or SSL even
	though not configured?</a></h2>

<p>Some options in fetchmail - including sslcertck that has become the
default in v6.4.0 - require fetchmail to negotiate SSL or TLS.
In other situations, fetchmail tries to negotiate SSL or TLS 
opportunistically: Some servers advertise STLS (POP3) or STARTTLS (IMAP),
and fetchmail will automatically attempt TLS negotiation if SSL was enabled at compile
time.  This can however cause problems if the upstream didn't configure
his certificates properly.</p>

<p>In some situations, the server does not offer STARTTLS or STLS, but
it would offer a TLS-wrapped operation on a dedicated, separate port.
In such a situation, adding <code>ssl</code> to the rcfile
(or <code>--ssl</code> on the command line) is all there is to it.
Fetchmail will use the default port for the "secure"
service and negotiate TLS or SSL right away.</p>

<p>In order to prevent fetchmail 6.4.0 and newer versions from trying
STLS or STARTTLS negotiation, and only as a last resort because it exposes
all communication to potential eavesdroppers, you could add this option:</p>
<pre>sslproto ''</pre>

<hr/>
<h1>Runtime fatal errors</h1>
<h2><a id="R1" name="R1">R1. Fetchmail isn't working, and -v shows
'SMTP connect failed' messages.</a></h2>

<p>Fetchmail itself is probably working, but your SMTP port 25
listener is down or inaccessible.</p>

<p>The first thing to check is if you can telnet to port 25 on your
smtp host (which is normally 'localhost' unless you've specified an
smtp option in your .fetchmailrc or on the command line) and get a
greeting line from the listener. If the SMTP host is inaccessible
or the listener is down, fix that first.</p>

<p>In Red Hat Linux 6.x, SMTP is disabled by default. To fix this,
set "DAEMON=yes" in your /etc/sysconfig/sendmail file, then restart
sendmail by running "/sbin/service sendmail restart".</p>

<p>If the listener seems to be up when you test with telnet, the
most benign and typical problem is that the listener had a
momentary seizure due to resource exhaustion while fetchmail was
polling it -- process table full or some other problem that stopped
the listener process from forking. If your SMTP host is not
'localhost' or something else in /etc/hosts, the fetchmail glitch
could also have been caused by transient nameserver failure.</p>

<p>Try running fetchmail -v again; if it succeeds, you had one of
these kinds of transient glitch. You can ignore these hiccups,
because a future fetchmail run will get the mail through.</p>

<p>If the listener tests up, but you have chronic failures trying
to connect to it anyway, your problem is more serious. One way to
work around chronic SMTP connect problems is to use --mda. But this
only attacks the symptom; you may have a DNS or TCP routing
problem. You should really try to figure out what's going on
underneath before it bites you some other way.</p>

<p>We have one report (from toby@eskimo.com) that you can sometimes
solve such problems by doing an <code>smtp</code> declaration with
an IP address that your routing table maps to something other than
the loopback device (he used ppp0).</p>

<p>We also have a report that this error can be caused by having an
/etc/hosts file that associates your client host name with more
than one IP address.</p>

<p>It's also possible that your DNS configuration isn't looking at
<code>/etc/hosts</code> at all. If you're using libc5, look at
<code>/etc/resolv.conf</code>; it should say something like:</p>

<pre>
        order hosts,bind
</pre>

<p>so your <code>/etc/hosts</code> file is checked first. If you're
running GNU libc6, check your <code>/etc/nsswitch.conf</code> file.
Make sure it says something like</p>

<pre>
        hosts:  files dns
</pre>

<p>again, in order to make sure <code>/etc/hosts</code> is seen
first.</p>

<p>If you have a hostname set for your machine, and this hostname
does not appear in /etc/hosts, you will be able to telnet to port
25 and even send a mail with rcpt to: user@host-not-in-/etc/hosts,
but fetchmail can't seem to get in touch with sendmail, no matter
what you set smtpaddress to.</p>

<p>We had another report from a Linux user of fetchmail 2.1 who
solved his SMTP connection problem by removing the reference to
-lresolv from his link line and relinking. Apparently in some older
Linux distributions the libc bind library version works better.</p>

<p>As of 2.2, the configure script has been hacked so the bind
library is linked only if it is actually needed. So under Linux it
won't be, and this particular cause should go away.</p>

<h2><a id="R2" name="R2">R2. When I try to configure an MDA,
fetchmail doesn't work.</a></h2>

<p>(I hear this one from people who have run into the blank-line
problem in <a href="#X1">X1</a>.)</p>

<p>Try sending yourself test mail and retrieving it using the
command-line options '<code>-k -m cat</code>'. This will dump
exactly what fetchmail retrieves to standard output (plus the
Received line fetchmail itself adds to the headers).</p>

<p>If the dump doesn't match what shows up in your mailbox when you
configure an MDA, your MDA is mangling the message. If it doesn't
match what you sent, then fetchmail or something on the server is
broken.</p>

<h2><a id="R3" name="R3">R3. Fetchmail dumps core when given an
invalid rc file.</a></h2>

<p>Note that this bug should no longer occur when using prepackaged
fetchmail versions or installing unmodified original tarballs, since
these ship with a proper parser .c file.</p>

<p>This is usually reported from AIX or Ultrix, but has even been
known to happen on Linuxes without a recent version of
<code>flex</code> installed. The problem appears to be a result of
building with an archaic version of lex.</p>

<p>Workaround: fix the syntax of your .fetchmailrc file.</p>

<p>Fix: build and install the latest version of <a
    href="http://flex.sourceforge.net/">flex</a>.</p>

<h2><a id="R4" name="R4"><strike>R4. Fetchmail dumps core in -V mode, but
	operates normally otherwise.</strike></a></h2>

<p><em>The information that used to be here referred to bugs in Linux libc5
    systems, which are deemed obsolete by now.</em></p>

<h2><a id="R5" name="R5">R5. Running fetchmail in daemon mode
doesn't work.</a><br/>
</h2>

<p>We have one report from a SunOS 4.1.4 user that trying to run
fetchmail in detached daemon mode doesn't work, but that using the
same options with -N (nodetach) is OK. We have another report of
similar behavior from one Linux user, but many other Linux users
report no problem.</p>

<p>If this happens, you have a specific portability problem with
the code in daemon.c that detaches and backgrounds the daemon
fetchmail. The isolated Linux case has been chased down to a
failure in dup(2) that may reflect a glibc bug.</p>

<p>As a workaround, you can start fetchmail with -N and an
ampersand to background it. A Sun user recommends this:</p>

<pre>
(fetchmail --nodetach &lt;other params&gt; &amp;)
</pre>

<p>The extra pair of parens is significant --- it makes sure that
the process detaches from the initial shell (one more shell is
started and dies immediately, detaching fetchmail and making it
child of PID 1). This is important when you start fetchmail
interactively and than quit interactive shell. The line above makes
sure fetchmail lives after that!</p>

<h2><a id="R6" name="R6">R6. Fetchmail randomly dies with socket
errors.</a></h2>

<p>Check the MTU value in your PPP interface reported by
<code>/sbin/ifconfig</code>. If it's over 600, change it in your
PPP options file. (<code>/etc/ppp/options</code> on my box). Here
are option values that work:</p>

<p>Another circumstance that can trigger this is if you are polling
a virtual-mail-server name that is round-robin connected to
different actual servers, so you get different IP addresses on
different poll cycles. To work around this, change the poll name
either to the real name of one of the servers in the ring or to a
corresponding IP address.</p>

<h2><a id="R7" name="R7">R7. Fetchmail running as root stopped
working after an OS upgrade</a></h2>

<p>In RH 6.0, the HOME value in the boot-time root environment
changed from /root to / as the result of a change in init. Move
your .fetchmailrc or use a -f option to explicitly point at the
file. (Oddly, a similar problem has been reported from Debian
systems.)</p>

<h2><a id="R8" name="R8">R8. Fetchmail is timing out after fetching
certain messages but before deleting them</a></h2>

<p>There's a TCP/IP stalling problem under Redhat Linux 6.0 that can cause this symptom. Brian Boutel
writes:</p>

<blockquote>
<p>TCP timestamps are turned on on my Linux boxes (I assume it's
now the default). This uses 12 extra bytes per segment. When the
tcp connection starts, the other end agrees a MSS of 1460, and then
fragments 1460 byte chunks into 1448 and 12, because is is not
allowing for the timestamp.</p>

<p>Then, for reasons I can't explain, it waits a long time
(typically 2 minutes) after the ack is sent before sending the next
(fragmented) packet. Turning off tcp timestamps avoids the
fragmentation and restores normal behaviour. To do this,
[execute]</p>

<p>echo 0 &gt; /proc/sys/net/ipv4/tcp_timestamps</p>

<p>I'm still unclear about the details of why this is happening. At
least [now] I am now getting good performance and no queue
blocking.</p>
</blockquote>

<h2><a id="R9" name="R9">R9. Fetchmail is timing out during message
fetches</a></h2>

<p>This is probably a general networking issue. Sending a "RETR"
command will cause the server to start sending large amounts of
data, which means large packets. If your networking layer has a
packet-fragmentation problem or improper firewall settings break Path
MTU discovery (when for instance all ICMP traffic is blocked), that's
where you'll see it.</p>

<h2><a id="R10" name="R10"><strike>R10. Fetchmail is dying with
	SIGPIPE.</strike></a></h2>

<p><em>Fetchmail 6.3.5 and newer block SIGPIPE, and many older versions have
  already handled this signal, so you shouldn't be seeing SIGPIPE
at all.</em></p>

<h2><a id="R11" name="R11">R11. My server is hanging or emitting
errors on CAPA.</a></h2>

<p>Your POP3 server is broken. You can work around this with the
declaration <tt>auth password</tt> in your .fetchmailrc.</p>

<h2><a id="R12" name="R12">R12. Fetchmail isn't working and reports
	getaddrinfo errors.</a></h2>
<ol><li>Make sure you haven't mistyped the host name or address, and that
    your DNS is working. If you cannot fix DNS, give the numeric host
    literal, for instance, 192.168.0.1</li>
    <li>Make sure your <code>/etc/services</code> file (or other
    services database) contains the necessary service entries. If you
    cannot fix the services database, use the --service option and give the
    numeric port address. Common port addresses are:<table
	summary="Common port addresses for IMAP, POP3 and their SSL
	complements.">
	<tr><th>service</th><th>port</th></tr>
	<tr><td>IMAP</td><td>143</td></tr>
	<tr><td>IMAP+SSL</td><td>993</td></tr>
	<tr><td>POP3</td><td>110</td></tr>
	<tr><td>POP3+SSL</td><td>995</td></tr>
</table></li></ol>

<h2><a id="R13" name="R13">R13. What does "Interrupted system call"
	mean?</a></h2>

<p>Non-fatal signals (such as timers set by fetchmail itself) can
interrupt long-running functions and will then be reported as
"Interrupted system call". These can sometimes be timeouts.</p>

<h2><a id="R14" name="R14">R14. Since upgrading fetchmail/OpenSSL, I can no longer connect!</a></h2>

<p>If the upgrade you did encompassed an upgrade to OpenSSL 1.0.0 or newer, you
may need to run <code>c_rehash</code> on your certificate directories,
particularly if you are using local certs directories (f. i. through fetchmail's <code>--sslcertpath</code> option).</p>

<p>Reason: OpenSSL 1.0.0, relative to earlier versions, uses a different hash
for the symbolic links (symlinks) in its <code>certs/</code> directory, so you
need to recreate the symlinks by running <kbd>c_rehash
	/etc/ssl/certs</kbd> (adjust this to where your installation keeps its
certificates), and you cannot easily share this certs directory with
applications linked against older OpenSSL versions.</p>

<p>Note: OpenSSL's <code>c_rehash</code> script is broken in several versions,
which can cause malfunction if several OpenSSL tools versions are installed in
parallel in separate directories. In such cases, you may need a workaround to
get things going. Assuming your OpenSSL 1.1.1 is installed in
<code>/opt/openssl1.1.1</code> and your certificates are in
<code>/home/hans/certs</code>, you'd do this (the corresponding fetchmail
option is <kbd>--sslcertpath /home/hans/certs</kbd> on the commandline and
<kbd>sslcertpath /home/hans/cert</kbd> in the rcfile):</p>

<pre>
env PATH=/opt/openssl1.1.1/bin /opt/openssl1.1.1/bin/c_rehash /home/hans/certs
</pre>

<h2><a id="R15" name="R15">R15. Help, I'm getting Authorization failure!</a></h2>

<p>First, try upgrading to fetchmail 6.3.18 or newer. Release 6.3.18 has
received a considerable number of bug fixes for the authentication
feature (AUTH, AUTHENTICATE, SASL). Most notably, fetchmail aborts SASL
authentication attempts properly with an asterisk if it detects that it
cannot make progress with a particular authentication scheme. This fixes
issues where GSSAPI-enabled fetchmail cannot authenticate against
Microsoft Exchange 2007 and 2010. <strong>Note</strong> that this is a
bug in old fetchmail versions!</p>

<p>Fetchmail by default attempts to authenticate using various schemes.
Fetchmail tries these schemes in order of descending security, meaning
the most secure schemes are tried first.</p>

<p>However, sometimes the server offers a secure authentication scheme
that is not properly configured, or an authentication scheme such as
GSSAPI that requires credentials to be acquired externally. In some
situations, fetchmail cannot know that the scheme will fail beforehand,
without trying it. In most cases, fetchmail should proceed to the next
authentication scheme automatically, but this sometimes does not
work.</p>

<p><strong>Solution:</strong> Configure the right authentication scheme
explicitly, for instance, with <kbd>--auth cram-md5</kbd> or <kbd>--auth
    password</kbd> on the command line or <code>auth "cram-md5"</code> or
	<code>auth "password"</code> in the rcfile. Details can be found
	in the manual page.<br />
	<strong>Note</strong> that auth password should only be used
	across secure links (see the sslcertck and ssl/sslproto options).
	</p>

<hr/>
<h1>Hangs and lockups</h1>
<h2><a id="H1" name="H1">H1. Fetchmail hangs when used with
pppd.</a></h2>

<p>Your problem may be with pppd's 'demand' option. We have a
report that fetchmail doesn't play well with it, but works with
pppd if 'demand' is turned off. We have no idea why this is.</p>

<h2><a id="H2" name="H2">H2. Fetchmail hangs during the MAIL FROM
exchange.</a></h2>

<p>The symptom: 'fetchmail -v' retrieves mail fine, but appears to
hang after sending the MAIL FROM command</p>

<pre>
SMTP&gt; MAIL FROM: &lt;someone@somewhere&gt;
</pre>

<p>The hang is actually occuring when sendmail looks up a sender's
address in DNS. The problem isn't in fetchmail but in the
configuration of sendmail. You must enable the 'nodns' and
'nocanonify' features of sendmail.</p>

<p>Here was my fix for RedHat 7.2:</p>

<li># cp sendmail.mc sendmail-mine.mc</li>

<li>Edit sendmail-mine.mc and add lines:

<pre>
   FEATURE(nodns)
   FEATURE(nocanonify)
</pre>
</li>

<li>Build a new sendmail.cf

<pre>
   # m4 sendmail-mine.cf &gt; /etc/sendmail.cf
</pre>
</li>

<li>Restart sendmail.</li>
</ol>

<p>For more details consult the file
/usr/share/sendmail-cf/README.</p>

<h2><a id="H3" name="H3">H3. Fetchmail hangs while fetching
mail.</a></h2>

<p>Symptom: 'fetchmail -v' retrieves the first few messages,
but hangs returning:</p>

<pre>
 fetchmail: SMTP&lt; 550 5.0.0 Access denied
 fetchmail: SMTP&gt; RSET
 fetchmail: SMTP&lt; 250 2.0.0 Reset state
 .......fetchmail:  flushed
 fetchmail: POP3&gt; DELE 1
 fetchmail: POP3&lt; +OK marked deleted
</pre>

<p>Check and see if you're allowing sendmail connections through
TCP wrappers.</p>

<p>Adding 'sendmail : 127.0.0.1' to /etc/hosts.allow could solve
this problem.</p>

<hr/>
<h1>Disappearing mail</h1>
<h2><a id="D1" name="D1">D1. I think I've set up fetchmail
correctly, but I'm not getting any mail.</a></h2>

<p>Maybe you have a .forward or alias set up that you've forgotten
about. You should probably remove it.</p>

<p>Or maybe you're trying to run fetchmail in multidrop mode as
root without a .fetchmailrc file. This doesn't do what you think it
should; see question <a href="#C1">C1</a>.</p>

<p>Or you may not be connecting to the SMTP listener. Run fetchmail
-v and see <a href="#R1">R1</a>.</p>

<p>Or you may have your local user set incorrectly. In the
following line</p>

<pre>
        user 'remoteuser' there with password '*' is 'localuser' here
</pre>

<p>make sure that 'localuser' does exist and can receive mail.</p>

<h2><a id="D2" name="D2">D2. All my mail seems to disappear after a
dropped connection.</a></h2>

<p>One POP3 daemon used in the Berkeley Unix world that reports
itself as POP3 version 1.004 actually throws the queue away. 1.005
fixed that. If you're running this one, upgrade immediately. (It
also truncates long lines at column 1024.)</p>

<p>Many POP servers, if an interruption occurs, will restore the
whole mail queue after about 10 minutes. Better ones will restore it
right away. If you have an interruption and don't see it right
away, cross your fingers and wait ten minutes before retrying.</p>

<p>Good servers are designed to restore the entire queue, including
messages you have deleted. If you have one of these and it flakes out on
you a lot, try setting a small <code>--fetchlimit</code> value. This
will result in more IP connects to the server, but will mean it actually
executes changes to the queue more often.</p>

<h2><a id="D3" name="D3">D3. Mail that was being fetched when I
interrupted my fetchmail seems to have been vanished.</a></h2>

<p>Fetchmail only sends a delete mail request to the server when
either (a) it gets a positive delivery acknowledgment from the SMTP
listener, or (b) it gets one of the spam-filter errors (see the
description of the <code>antispam&gt;</code> option) from the
listener. No interrupt can cause it to lose mail.</p>

<p>However, IMAP2bis has a design problem in that its normal fetch
command marks a message 'seen' as soon as the fetch command to get
it is sent down. If for some reason the message isn't actually
delivered (you take a line hit during the download, or your port 25
listener can't find enough free disk space, or you interrupt the
delivery in mid-message) that 'seen' message can lurk invisibly in
your server mailbox forever.</p>

<p>Workaround: add the '<code>fetchall</code>' keyword to your
fetch options.</p>

<p>Solution: switch to an IMAP4 server.</p>

<hr/>
<h1>Multidrop-mode problems</h1>
<h2><a id="M0" name="M0">M0. What about multidrop, anyways?</a></h2>

<p>Multidrop is a way to receive mail for several receivers in one
mailbox. It is sort of abusing the system (using address extensions
would be more useful, where available) and has quite some
requirements to work properly. I wrote a separate article to document
this, it is avavailable <a href="multidrop.html"> in English </a>
and <a href="multidrop.de.html"> in German.</a></p>

<h2><a id="M1" name="M1">M1. I've declared local names, but all my
multidrop mail is going to root anyway.</a></h2>

<p>Somehow your fetchmail is never recognizing the hostname part of
recipient names it parses out of Envelope-header lines (or these are
improperly configured) as
matching a name within the designated domains. To check this, run
fetchmail in foreground with -v -v on. You will probably see a lot
of messages with the format "line rejected, %s is not an alias of
the mailserver" or "no address matches; forwarding to %s."</p>

<p>These errors usually indicate some kind of configuration
problem.</p>

<p>The easiest workaround is to add a '<code>via</code>' option (if
necessary) and add enough '<code>aka</code>' declarations to cover all
of your mailserver's aliases, then say '<code>no dns</code>'. This will
take DNS out of the picture (though it means mail may be uncollected if
it's sent to an alias of the mailserver that you don't have listed).</p>

<p>Occasionally these errors indicate the sort of header-parsing
problem described in <a href="#M7">M7</a>.</p>

<h2><a id="M2" name="M2">M2. I can't seem to get fetchmail to route
to a local domain properly.</a></h2>

<p>A lot of people want to use fetchmail as a poor man's
internetwork mail gateway, picking up mail accumulated for a whole
domain in a single server mailbox and then routing based on what's
in the To/Cc/Bcc lines.</p>

<p>In general, this is not really a good idea. It would be smarter
to just let the mail sit in the mailserver's queue and use
fetchmail's ETRN or ODMR modes to trigger SMTP sends periodically
(of course, this means you have to poll more frequently than the
mailserver's expiration period). If you can't arrange this, try
setting up a UUCP feed.</p>

<p>If neither of these alternatives is available, multidrop mode
may do (though you <em>are</em> going to get hurt by some mailing
list software; see the caveats under THE USE AND ABUSE OF MULTIDROP
MAILBOXES on the man page, and check what is needed at <a
    href="http://home.pages.de/~mandree/mail/multidrop">Matthias
    Andree's &quot;Requisites for working multidrop
    mailboxes&quot;</a>). If you want to try it, the way to do it is
with the '<code>localdomains</code>' option.</p>

<p>In general, if you use localdomains you need to make sure of two
other things:</p>

<p><strong>1. You've actually set up your .fetchmailrc entry to
invoke multidrop mode.</strong></p>

<p>Many people set a '<code>localdomains</code>' list and then
forget that fetchmail wants to see more than one name (or the
wildcard '*') in a '<code>here</code>' list before it will do
multidrop routing.</p>

<p><strong>2. You may have to set 'no envelope'.</strong></p>

<p>Normally, multidrop mode tries to deduce an envelope address
from a message before parsing the To/Cc/Bcc lines (this enables it
to avoid losing to mailing list software that doesn't put a
recipient address in the To lines).</p>

<p>Some ways of accumulating a whole domain's messages in a single
server mailbox mean it all ends up with a single envelope address
that is useless for rerouting purposes. In this particular case, sell
your ISP a clue. If that does not work, you may have to set
'<code>no envelope</code>' to prevent fetchmail from being
bamboozled by this, but a missing envelope makes multidrop routing
unreliable.</p>

<p>Check also answer <a href="#T1">T1</a> on a reliable way to do
multidrop delivery if your ISP (or your mail redirection provider)
is using qmail.</p>

<h2><a id="M3" name="M3">M3. I tried to run a mailing list using
multidrop, and I have a mail loop!</a></h2>

<p>This isn't fetchmail's fault. Check your mailing list. If the
list expansion includes yourself or anybody else at your mailserver
(that is, not on the client side) you've created a mail loop. Just
chop the host part off any local addresses in the list.</p>

<p>If you use sendmail, you can check the list expansion with
<code>sendmail -bv</code>.</p>

<h2><a id="M4" name="M4"><strike>M4. My multidrop fetchmail seems to be
having DNS problems.</strike></a></h2>

<p><em>The answer that used to be here no longer applies to
    fetchmail.</em></p>

<h2><a id="M5" name="M5">M5. I'm seeing long DNS delays before each
message is processed.</a></h2>

<p>Use the '<code>aka</code>' option to pre-declare as many of your
mailserver's DNS names as you can. When an address's host part
matches an aka name, no DNS lookup needs to be done to check
it.</p>

<p>If you're sure you've pre-declared all of your mailserver's DNS
names, you can use the '<code>no dns</code>' option to prevent
other hostname parts from being looked up at all.</p>

<p>Sometimes delays are unavoidable. Some SMTP listeners try to
call DNS on the From-address hostname as a way of checking that the
address is valid.</p>

<h2><a id="M6" name="M6">M6. How do I get multidrop mode to work
with majordomo?</a></h2>

<p>In order for sendmail to execute the command strings in the
majordomo alias file, it is necessary for sendmail to think that
the mail it receives via SMTP really is destined for a local user
name. A normal virtual-domain setup results in delivery to the
default mailbox, rather than expansion through majordomo.</p>

<p>Michael &lt;michael@bizsystems.com&gt; gave us a recipe for
dealing with this case that pairs a run control file like this:</p>

<pre>
poll your.pop3.server proto pop3:
    no envelope no dns
    localdomains virtual.localdomain1.com virtual.localdomain2.com ...
    user yourISPusername is root * here,
    password yourISPpassword fetchall
</pre>

<p>with a hack on your local sendmail.cf like this:</p>

<pre>
#############################################
#  virtual info, local hack for ruleset 98  #
#############################################

# domains to treat as direct mapped local domain

CVvirtual.localdomain1.com virtual.localdomain2.com ...
---------------------------
in ruleset 98 add
-------------------------
# handle virtual users

R$+ &lt;@ $=V . &gt;          $: $1 &lt; @ $j . &gt;
R&lt; @ &gt; $+ &lt; @ $=V . &gt;   $: $1 &lt; @ $j . &gt;
R&lt; @ &gt; $+               $: $1
R&lt; error : $- $+ &gt; $*   $#error $@ $1 $: $2
R&lt; $+ &gt; $+ &lt; @ $+ &gt;     $: $&gt;97 $1
</pre>

<p>This ruleset just strips virtual domain names off the addresses
of incoming mail. Your sendmail must be 8.8 or newer for this to
work. Michael says:</p>

<blockquote>I use this scheme with 2 virtual domains and the
default ISP user+domain and service about 30 mail accounts +
majordomo on my inside pop3 server with fetchmail and sendmail
8.83</blockquote>

<h2><a id="M7" name="M7">M7. Multidrop mode isn't parsing envelope
addresses from my Received headers as it should.</a></h2>

<p>It may happen that you're getting what appear to be well-formed
sendmail Received headers, but fetchmail can't seem to extract an
envelope address from them. There can be a couple of reasons for
this.</p>

<h3>Spurious Received lines need to be skipped:</h3>

<p>First, fetchmail might be looking at the wrong Received header.
Normally it looks only on the first one it sees, on the theory that
that one was last added and is going to be the one containing your
mailserver's theory of who the message was addressed to.</p>

<p>Some (unusual) mailserver configurations will generate extra
Received lines which you need to skip. To arrange this, use the
optional skip prefix argument of the 'envelope' option; you may
need to say something like '<code>envelope 1 Received</code>' or
'<code>envelope 2 Received</code>'.</p>

<h3>The 'by' clause doesn't contain a mailserver alias:</h3>

<p>When fetchmail parses a Received line that looks like</p>

<pre>
Received: from send103.yahoomail.com (send103.yahoomail.com [205.180.60.92])
    by iserv.example.net (8.8.5/8.8.5) with SMTP id RAA10088
    for &lt;ksturgeon@fbceg.example.org&gt;; Wed, 9 Sep 1998 17:01:59 -0700
</pre>

<p>it checks to see if 'iserv.example.net' is a DNS alias of your
mailserver before accepting 'ksturgeon@fbceg.example.org' as an envelope
address. This check might fail if your DNS were misconfigured, or
if you were using 'no dns' and had failed to declare iserv.example.net
as an alias of your server. The typical hint is logging similar to:
<code>line rejected, iserv.example.net is not an alias of the mailserver</code>,
if you use fetchmail in verbose mode.</p>

<p><strong>Workaround:</strong> You can specify the alias explicitly, with <code>aka
    <em>iserv.example.net</em></code> statements in the rcfile. Replace
<em>iserv.example.net</em> by the name you find in <strong>your</strong>
'by' part of the 'Received:' line.</p>

<h2><a id="M8" name="M8">M8. Users are getting multiple copies of
messages.</a></h2>

<p>It's a consequence of multidrop. What's happening is that you
have N users subscribed to the same list. The list software sends N
copies, not knowing they will end up in the same multidrop box.
Since they are both locally addressed to all N users, fetchmail
delivers N copies to each user.</p>

<p>Fetchmail tries to eliminate adjacent duplicate messages in a
multidrop mailbox. However, this logic depends on the message-ID
being identical in both copies. It also depends on the two copies
being adjacent in the server mailbox. The former is usually the
case, but the latter condition sometimes fails in a
timing-dependent way if the server was processing multiple incoming
mail streams.</p>

<p>I could eliminate this problem by keeping a list of all
message-IDs received during a poll so far and dropping any message
that matches a seen mail ID. The trouble is that this is an O(N**2)
operation that might significantly slow down the retrieval of large
mail batches.</p>

<p>The real solution however is to make sure that fetchmail can find the
envelope recipient properly, which will reliably prevent this message
duplication.</p>

<hr/>
<h1>Mangled mail</h1>
<h2><a id="X1" name="X1">X1. Spurious blank lines are appearing in
the headers of fetched mail.</a></h2>

<p>What's probably happening is that the POP/IMAP daemon on your
mailserver is inserting a non-RFC822 header (like X-POP3-Rcpt:) and
something in your delivery path (most likely an old version of the
<em>deliver</em> program, which sendmail often calls to do local
delivery) is failing to recognize it as a header.</p>

<p>This is not fetchmail's problem. The first thing to try is
installing a current version of <em>deliver</em>. If this doesn't
work, try to figure out which other program in your mail path is
inserting the blank line and replace that. If you can't do either
of these things, pick a different MDA (such as maildrop) and
declare it with the '<code>mda</code>' option.</p>

<h2><a id="X2" name="X2">X2. My mail client can't see a Subject
line.</a></h2>

<p>First, see <a href="#X1">X1</a>. This is quite probably the same
problem (X-POP3-Rcpt header or something similar being inserted by
the server and choked on by an old version of
<em>deliver</em>).</p>

<p>The O'Reilly sendmail book does warn that IDA sendmail doesn't
process X- headers correctly. If this is your problem, all I can
suggest is replacing IDA sendmail, because it's broken and not
RFC822 conformant.</p>

<h2><a id="X3" name="X3">X3. Messages containing "From" at the start of
	line are being split.</a></h2>

<p>If you know the messages aren't split in your server mailbox,
then this is a problem with your POP/IMAP server, your client-side
SMTP listener or your local delivery agent. Fetchmail cannot split
messages.</p>

<p>Some POP server daemons ignore Content-Length headers and split
messages on From lines. We have one report that the 2.1 version of
the BSD popper program (as distributed on Solaris 2.5 and
elsewhere) is broken this way.</p>

<p>You can test this. Declare an mda of 'cat' and send yourself one
piece of mail containing "From" at start of a line. If you see a
split message, your POP/IMAP server is at fault. Upgrade to a more
recent version.</p>

<p>Sendmail and other SMTP listeners don't split RFC822 messages
either. What's probably happening is either sendmail's local
delivery agent or your mail reader are not quite RFC822-conformant
and are breaking messages on what it thinks are Unix-style From
headers. You can figure out which by looking at your client-side
mailbox with vi or more. If the message is already split in your
mailbox, your local delivery agent is the problem. If it's not,
your mailreader is the problem.</p>

<p>If you can't replace the offending program, take a look at your
sendmail.cf file. There will likely be a line something like</p>

<pre>
Mlocal, P=/usr/bin/procmail, F=lsDFMShP, S=10, R=20/40, A=procmail -Y -d $u
</pre>

<p>describing your local delivery agent. Try inserting the 'E'
option in the flags part (the F= string). This will make sendmail
turn each dangerous start-of-line From into a &gt;From, preventing
programs further downstream from acting up.</p>

<h2><a id="X4" name="X4">X4.</a> <a id="generic_mangling"
name="generic_mangling">My mail is being mangled in a new and
different way</a></h2>

<p>The first thing you need to do is pin down what program is doing
the mangling. We don't like getting bug reports about fetchmail
that are actually due to some other program's malfeasance, so
please go through this diagnostic sequence before sending us a
complaint.</p>

<p>There are five possible culprits to consider, listed here in the
order they pass your mail:</p>

<ol>
<li>Programs upstream of your server mailbox.</li>

<li>The POP or IMAP server on your mailserver host.</li>

<li>The fetchmail program itself.</li>

<li>Your local sendmail.</li>

<li>Your LDA (local delivery agent), as called by sendmail or
specified by <code>mda</code>.</li>
</ol>

<p>Often it happens that fetchmail itself is OK, but using it
exposes pre-existing bugs in your downstream software, or your
downstream software has a bad interaction with POP/IMAP. You need
to pin down exactly where the message is being garbled in order to
deduce what is actually going on.</p>

<p>The first thing to do is send yourself a test message, and
retrieve it with a .fetchmailrc entry containing the following (or
by running with the equivalent command-line options):</p>

<pre>
    mda "cat &gt;MBOX" keep fetchall
</pre>

<p>This will capture what fetchmail gets from the server, except
for (a) the extra Received header line fetchmail prepends, (b)
header address changes due to <code>rewrite</code>, and (c) any
end-of-line changes due to the <code>forcecr</code> and
<code>stripcr</code> options. MBOX will in fact contain what
programs downstream of fetchmail see.</p>

<p>The most common causes of mangling are bugs and
misconfigurations in those downstream programs. If MBOX looks
unmangled, you will know that is what is going on and that it is
not fetchmail's problem. Take a look at the other FAQ items in this
section for possible clues about how to fix your problem.</p>

<p>If MBOX looks mangled, the next thing to do is compare it with
your actual server mailbox (if possible). That's why you specified
<code>keep</code>, so the server copy would not be deleted. If your
server mailbox looks mangled, programs upstream of your server
mailbox are at fault. Unfortunately there is probably little you
can do about this aside from complaining to your site postmaster,
and nothing at all fetchmail can do about it!</p>

<p>More likely you'll find that the server copy looks OK. In that
case either the POP/IMAP server or fetchmail is doing the mangling.
To determine which, you'll need to telnet to the server port and
simulate a fetchmail session yourself. This is not actually hard
(both POP3 and IMAP are simple, text-only, line-oriented protocols)
but requires some attention to detail. You should be able to use a
fetchmail -v log as a model for a session, but remember that the
"*" in your LOGIN or PASS command dump has to be replaced with your
actual password.</p>

<p>The objective of manually simulating fetchmail is so you can see
exactly what fetchmail sees. If you see a mangled message, then
your server is at fault, and you probably need to complain to your
mailserver administrators. However, we like to know what the broken
servers are so we can warn people away from them. So please send us
a transcript of the session including the mangling <em>and the
server's initial greeting line</em>. Please tell us anything else
you think might be useful about the server, like the server host's
operating system.</p>

<p>If your manual fetchmail simulation shows an unmangled message,
congratulations. You've found an actual fetchmail bug, which is a
pretty rare thing these days. Complain to us and we'll fix it.
Please include the session transcript of your manual fetchmail
simulation along with the other things described in the FAQ entry
on <a href="#G3">reporting bugs</a>.</p>

<h2><a id="X5" name="X5"><strike>X5. Using POP3, retrievals seems to be
	fetching too much!</strike></a></h2>

<p><em>The information that used to be here pertained to fetchmail 4.4.7 or
    older, which should not be used. Use a recent fetchmail version.</em></p>

<h2><a id="X6" name="X6">X6. My mail attachments are being dropped
or mangled.</a></h2>

<p>Fetchmail doesn't discard attachments; fetchmail doesn't have any idea
that attachments are there.  Fetchmail treats the body of each message as
an uninterpreted byte stream and passes it through without alteration.
If you are not receiving attachments through fetchmail, it is because
your mailserver is not sending them to you.</p>

<p>The fix for this is to replace your mailserver with one that works.
If its operating system makes this difficult, you should replace its
operating system with one that works. Windows- and NT-based POP servers
seem especially prone to mangle attachments. If you are running one
of these, replacing your server with a Unix machine is probably the
only effective solution.</p>

<p>We've had sporadic reports of problems with Microsoft Exchange and
Outlook servers.  These sometimes randomly fail to ship
attachments to your client.  This is a known bug, acknowledged by
Microsoft.</p>

<p>They may also mangle the attachments they do pass through.  If you
see unreadable attachments with a ContentType of "application/x-tnef",
you're having this problem.  The <a
href="http://world.std.com/~damned/software.html">TNEF</a> utility may
help.</p>

<p>The Mail Max POP3 server and the InterChange and Imail IMAP
servers are known to simply drop MIME attachments when uploading
messages.</p>

<p>We've also had a report that Lotus Notes sometimes trashes the
MIME type of messages. In particular, it seems to modify MIME
headers of type application/pdf, mangling the type to
application/octet-stream. It may corrupt other MIME types as
well.</p>

<p>The IMAP service of Lotus Domino has a known bug in the way it
generates MIME Content-type headers (observed on Lotus Domino
5.0.2b). It's a subtle one that doesn't show up when Netscape
Messenger and other clients use a FETCH BODY[] to grab the whole
message. When fetchmail uses FETCH RFC822.HEADER and FETCH
RFC822.TEXT to get first the header and then the body, Domino
generates different Boundary tags for each part, e.g. one tag is
declared in the Content-type header and another is used to separate
the MIME parts in the body. This doesn't work. (I have heard a
rumor that this bug is scheduled to be fixed in Domino release 6;
you can find a workaround at contrib/domino.)</p>

<p>Rob Funk explains: Unfortunately there also remain many mail
user agents that don't write correct MIME messages. One big
offender is Sun MailTool attachments, which are formatted enough
like MIME that some programs could get confused; these are
generated by the mailtool and dtmail programs (the mail programs in
Sun's OpenWindows and CDE environments).</p>

<p>One solution to problems related to misformatted MIME
attachments is the <a
href="ftp://ftp.uu.se/pub/unix/networking/mail/emil/">emil</a>
program; see its <a
href="ftp://ftp.uu.se/pub/unix/networking/mail/emil/TUTORIAL.html">tutorial</a>
file at that site for details on emil. It is useful for converting
character sets, attachment encodings, and attachment formats. At
this writing, emil does not appear to have been maintained since a
patch to version 2.1.0beta9 in late 1997, but it is still
useful.</p>

<p>One good way of using emil is from within procmail. You can have
procmail look for signs of problematic message formatting, and pipe
those messages through emil to be fixed. emil will not always be
able to fix the problem, in which case the message is
unchanged.</p>

<p>A possible rule to be inserted into a .procmailrc file for using
emil would be:</p>

<pre>
:0HB
* 1^1 ^Content-Type: \/X-sun[^;]*
* 1^1 ^Content-Type: \/application/mac-binhex[^;]*
* 1^1 ^Content-Transfer-Encoding: \/x-binhex[^;]*
* 1^1 ^Content-Transfer-Encoding: \/x-uuencode[^;]*
{
  LOG="Converting $MATCH
"
  :0fw
  | emil -A B -T Q -B BA -C iso-8859-1 -H Q -F MIME \
  | gawk '{gsub(/\r\n?/,"\n");print $0}'
}
</pre>

<p>The "1^1" in the conditions is a way of specifying to procmail
that if any one of the four listed expressions is found in the
message, the total condition is considered true, and the message
gets passed into emil. These four subconditions check whether the
message has a Sun attachment, a binhex attachment, or a uuencoded
attachment; there are others that could be added to check these
things better and to check other relevant conditions. The "LOG="
line writes a line into the procmail log; the lone double-quote
beginning the following line makes sure the log entry gets an
end-of-line character. The call to gawk (GNU awk) is for fixing
end-of-line conventions, since emil sometimes leaves those in the
format of the originating machine; it could probably be replaced
with a sed subsitution.</p>

<p>The emil call itself tries to ensure that the message uses:</p>

<ul>
<li>BinHex encoding for any Apple Macintosh-only attachments</li>

<li>Quoted-Printable encoding for text (when necessary)</li>

<li>Base64 Encoding for binary attachments</li>

<li>iso-8859-1 character set for text (unfortunately emil can't yet
convert from windows-1252 to iso-8859-1)</li>

<li>Quoted-Printable encoding for headers</li>

<li>MIME attachment format</li>
</ul>

<p>Most of these (the primary exceptions being the character set
and the Apple binary format) are as they should be for good
internet interoperability.</p>

<p>Some mail servers (Lotus Domino is a suspect here) mangle
Sun-formatted messages, so the conversion to MIME needs to happen
before such programs see the message. The ideal is to rid the world
of Sun-formatted messages: don't use mailtool for sending
attachments (it doesn't understand MIME anyway, and most of the
world doesn't understand its attachments, so it really shouldn't be
used at all), and make sure dtmail is set to use MIME rather than
mailtool's format.</p>

<h2><a id="X7" name="X7">X7. Some mail attachments are hanging
fetchmail.</a></h2>

<p>Fetchmail doesn't know anything about mail attachments and doesn't
treat them any differently from plain message data.</p>

<p>The most usual cause of this problem seems to be bugs in your
network transport layer's capability to handle the very large
TCP/IP packets that attachments tend to turn into. You can test
this theory by trying to download the offending message through a
webmail account; using HTTP for the message tends to simulate
large-packet stress rather well, and you will probably find that
the messages that seem to be choking fetchmail will make your HTTP
download speed drop to zero.</p>

<p>This problem can be caused by subtle bugs in the
packet-reassembly layer of your TCP/IP stack; these often don't
manifest at normal packet sizes. It may also be caused by
malfunctioning path-MTU discovery on the mailserver. Or, if there's
a modem in the link, it may be because the attachment contains the
Hayes mode escape "+++".</p>

<h2><a id="X8" name="X8">X8. A spurious ) is being appended to my
messages.</a></h2>

<p><em>Fetchmail 6.3.5 and newer releases are supposed to fix this.</em></p>

<p>Due to the problem described in <a href="#S2">S2</a>, the
IMAP support in fetchmail cannot follow the IMAP protocol 100&nbsp;%.
Most of the time it doesn't matter, but if you combine it with an
SMTP server that behaves unusually, you'll get a spurious ) at
the message end.</p>

<p>One piece of software that can trigger this is the Interchange
mail server, as used by, e.g., mailandnews.com. Here's what
happens:</p>

<ol><li>Someone sends mail to your account. The last line of the
message contains text. So at the SMTP level, the message ends with,
e.g. "blahblah\r\n.\r\n"</li>

<li>The SMTP handler sees the final "\r\n.\r\n" and recognizes
the end of the message. However, instead of doing the normal thing,
which is tossing out the ".\r\n" and leaving the first '\r\n' as
part of the email body, Interchange throws out the whole
"\r\n.\r\n", and leaves the email body without any line terminator
at the end of it. RFC821 does not forbid this, though it probably
should.</li>

<li>Fetchmail, or some other IMAP client, asks for the message.
IMAP returns it, but it's enclosed inside parentheses, according to
the protocol. The message size in bytes is also present. Because
the message doesn't end with a line terminator, the IMAP client
sees:

<pre>
 ....blahblah)...
</pre>

<p>where the ')' is from IMAP.</p></li>

<li>Fetchmail only deals with complete lines, and can't trust the
stated message size because Microsoft Exchange goofs it up.</li>

<li>As a result, fetchmail takes the final 'blahblah)' and puts
it at the end of the message it forwards on. If you have verbosity
on, you'll get a message about actual != expected.</li>
</ol>

<h2><a id="X9" name="X9">X9. Missing "Content-Transfer-Encoding" header
	with Domino IMAP</a></h2>

<p>Domino 6 IMAP was found by Anthony Kim in February 2006 to
erroneously omit the "Content-Transfer-Encoding" header in messages
downloaded through IMAP, causing messages to display improperly. This
happened with Domino's incoming mail format configured to "Prefers
MIME". Solution: switch Domino to "Keep in Sender's format".</p>

<p>Reference: <a
    href="https://www.mhonarc.org/archive/html/fetchmail-friends/2006-03/msg00000.html">Anthony
    Kim's list post</a> 
</p>

<h2><a id="X10" name="X10">X10. Fetchmail delivers partial
	messages</a></h2>

<p>Fetchmail is sometimes reported to deliver partial messages. This
is usually related to network outages that occur while fetchmail is
downloading a message body. In such cases, fetchmail has downloaded a
complete header, so your header will be intact. The message body will be
truncated, and fetchmail will later attempt to redownload the
message (providing the server is standards conformant).</p>

<p>The reason for the truncation is that fetchmail streams the body
directly from the POP3/IMAP server into the SMTP/LMTP server or MDA (in
order to save memory), so fetchmail has already written a part of the
message before it notices it will be incomplete, and fetchmail cannot
abort a transaction it has started, and it's unclear if it ever will be
able to, because this is not standardized and the outcome will depend on
the receiving software (be it SMTP/LMTP or MDA).</p>

<hr/>
<h1>Other problems</h1>
<h2><a id="O1" name="O1">O1. The --logfile option doesn't work if
the logfile doesn't exist.</a></h2>

<p>This is a feature, not a bug. It's in line with normal practice
for system daemons and allows you to suppress logging by removing
the log file, without hacking potentially fragile startup scripts.
To get around it, just touch(1) the logfile before you run fetchmail
(this will have no effect on the contents of the logfile if it already
exists).</p>

<h2><a id="O2" name="O2">O2. Every time I get a POP or IMAP message,
the header is dumped to all my terminal sessions.</a></h2>

<p>Fetchmail uses the local sendmail to perform final delivery,
which Mozilla and other clients don't do; the announcement of
new messages is done by a daemon that sendmail pokes. There should
be a "biff" command to control this. Type</p>

<p>to turn it off. If this doesn't work, try the command</p>

<pre>
chmod -x $(tty)
</pre>

<p>which is essentially what <code>biff -n</code> will do. If this
doesn't work, comment out any reference to "comsat" in your
/etc/inetd.conf file and reload (or restart) inetd.</p>

<p>In Slackware Linux distributions, the last line in /etc/profile
is</p>

Change this to

to solve the problem system-wide.

<h2><a id="O3" name="O3">O3. Does fetchmail reread its rc file
every poll cycle?</a></h2>

<p>No, but versions 5.2.2 and later will notice when you modify
your rc file and restart, reading it. Note that this causes troubles if
you need to provide a password via the console, unless you're running in
--nodetach mode.</p>

<h2><a id="O4" name="O4">O4. Why do deleted messages show up again
when I take a line hit while downloading?</a></h2>

<p>According to the POP3 RFCs, deletes aren't actually performed
until you issue the end-of-session QUIT command. Fetchmail cannot
fix this, but there is a workaround: use the --expunge option with a
reasonably low figure that works for you. Try 10 for a start.</p>

<p>IMAP is less susceptible to this problem, because the "deleted"
message marks are persistent, but they aren't in POP3. Note that the
--expunge default for IMAP is different than the default for POP3.</p>

<p>If you get very unlucky, you might take a line hit in the window
between the delete and the expunge. If you've set a longer expunge
interval, the window gets wider. This problem should correct itself
the next time you complete a successful query.</p>

<h2><a id="O5" name="O5">O5. Why is fetched mail being logged with
my name, not the real From address?</a></h2>

<p>Because logging is done based on the address indicated by the
sending SMTP's MAIL FROM, and some listeners are picky about that
address.</p>

<p>Some SMTP listeners get upset if you try to hand them a MAIL
FROM address naming a different host than the originating site for
your connection. This is a feature, not a bug -- it's supposed to
help prevent people from forging mail with a bogus origin site.
(RFC 1123 says you shouldn't do this exclusion...)</p>

<p>Since the originating site of a fetchmail delivery connection is
localhost, this effectively means these picky listeners will barf
on any MAIL FROM address fetchmail hands them with an @ in it!</p>

<p>Versions 2.1 and up try the header From address first and fall
back to the calling-user ID. So if your SMTP listener isn't picky,
the log will look right.</p>

<h2><a id="O6" name="O6">O6. I'm seeing long sendmail delays or
hangs near the start of each poll cycle.</a></h2>

<p>Sendmail does a hostname lookup when it first starts up, and
also each time it gets a HELO in listener mode.</p>

<p>Your resolver configuration may be causing one of these lookups
to fail and time out. Check your <code>/etc/resolv.conf</code>,
<code>/etc/host.conf</code>, <code>/etc/nsswitch.conf</code> (if you
have the latter two) and you <code>/etc/hosts</code> files. Make sure
your hostname and fully-qualified domain name are both in
<code>/etc/hosts</code>, and that hosts is looked at before DNS is
queried. You probably also want your remote mail server(s) to be in the
hosts file.</p>

<p>You can suppress the startup-time lookup if need to by reconfiguring
with <code>FEATURE(nodns)</code>.</p>

<p>Configuring your bind library to cache DNS lookups locally may
help, and is a good idea for speeding up other services as well.
Switching to a faster MTA like <a
    href="http://www.postfix.org/">Postfix</a> might help.</p>

<h2><a id="O7" name="O7">O7. Why doesn't fetchmail deliver mail in
date-sorted order?</a></h2>

<p>Because that's not the order the server hands it to fetchmail
in.</p>

<p>Fetchmail getting mail from a POP server delivers mail in the
order that your server delivers mail. Fetchmail can't do anything
about this; it's a limitation of the underlying POP protocol.</p>

<p>In theory it might be possible for fetchmail in IMAP mode to
sort messages by date, but this would be in violation of two basics
of fetchmail's design philosophy: (a) to be as simple and
transparent a pipe as possible, and (b) to <em>hide</em>, rather
than emphasize, the differences between the remote-fetch protocols
it uses.</p>

<p>Re-ordering messages is a user-agent function, anyway.</p>

<h2><a id="O8" name="O8">O8. I'm using pppd. Why isn't my monitor
option working?</a></h2>

<p>There is a combination of circumstances that can confuse
fetchmail. If you have set up demand dialing with pppd, and pppd
has an idle timeout, and you have lcp-echo-interval set, then the
lcp-echo-interval time must be longer than the pppd idle timeout.
Otherwise it is going keep increasing the packet counters that
fetchmail relies upon, triggering fetchmail into polling after its
own delay interval and thus preventing the pppd link from ever
reaching its inactivity timeout.</p>

<h2><a id="O9" name="O9">O9. Why does fetchmail keep retrieving the
same messages over and over?</a></h2>

<p>First, check to see that you haven't enabled the
<cite>keep</cite> and <cite>fetchall</cite> option. If you have,
turn one of them off - which one, depends on why they have been set in
the first place, and to a lesser degree on the upstream server.</p>

<p>This can also happen when some other mail client is logged in to
your mail server, if it uses a simple exclusive-locking scheme (and
many, especially most POP3 servers, do exactly that). Your
fetchmail is able to retrieve the messages, but because the mailbox
is write-locked by the other instance yours can neither mark
messages seen or delete them. The solution is to either (a) wait
for the other client to finish, or (b) terminate it.</p>

<h2><a id="O10" name="O10"><strike>O10. Why is the received date on all my
	messages the same?</strike></a></h2>

<p><em>The answer that used to be here made no sense and was dropped.</em></p>

<h2><a name="O11">O11. I keep getting messages that say "Repoll
immediately" in my logs.</a></h2>

<p>This is your server barfing on the CAPA probe that fetchmail sends.
Because some servers like to drop the connection after that probe,
fetchmail will re-poll immediately with this probe defeated.</p>

<p>If you run fetchmail in daemon mode (say "set daemon 600"), you will
get the message only once per run.</p>

<p>If you set an authentication method explicitly (say, with
<code>auth password</code>), you will never get the message.</p>

<h2><a name="O12">O12. Fetchmail no longer expunges mail on a 451 SMTP response.</a></h2>

<p>This is a feature, not a bug.</p>

<p>Any 4xx response (like 451) indicates a transient (temporary) error.
This means that the mail could be accepted if retried later. Lookup
failures are normally transient errors as a mail should not get
rejected if a dns server is unreachable or down.</p>

<p>A permanent reject response is of the form 5xx (like 550).</p>

<p>You could tell your SMTP server to not lookup any addresses if you are
not keen on checking the sender addresses. This problem typically
occurs if your mail server is not checking the sender addresses, but
your local server is.</p>

<p>Or you could declare <code>antispam 451</code>, which is not
recommended though, as it may cause mail loss.</p>

<p>Or, you could check your nameserver configuration and query logs for
dns errors.</p>

<p>All these issues are not related to fetchmail directly.</p>

<h2><a name="O13">O13. I want timestamp information in my fetchmail logs.</a></h2>

<p>Write a <code>preconnect</code> command in your configuration file that
does something like "date &gt;&gt; $HOME/fetchmail.log".</p>

<h2><a name="O14">O14. Fetchmail no longer deletes oversized mails with
--flush.</a></h2>

<p>Use <code>--limitflush</code> (available since release 6.3.0) to
delete oversized mails along with the <code>--limit</code> option. If
you are already having <code>flush</code> in your rcfile to delete
oversized mails, <em>replace</em> it with <code>limitflush</code> to
avoid losing mails unintentionally.</p>

<p>The <code>--flush</code> option is primarily designed to delete
mails which have been read/downloaded but not deleted yet. This option
cannot be overloaded to delete oversized mails as it cannot be guessed
whether the user wants to delete only read/downloaded mails or only
oversized mails or both when a user specifies both
<code>--limit</code> and <code>--flush</code>. Hence, a separate
<code>--limitflush</code> has been added to resolve the ambiguity.</p>

<h2><a name="O15">O15. Fetchmail always retains the first message in the
    mailbox.</a></h2>

<p>This happens when fetchmail sees an "X-IMAP:" header in the very
first message in your mailbox. This usually stems from a message like
the one shown below, which is automatically created on your server. This
message shows up if the University of Washington IMAP or PINE software
is used on the server together with a POP2 or POP3 daemon that is not
aware of these messages, such as some versions of Qualcomm Popper
(QPOP):</p>

<blockquote>
<pre>
From MAILER-DAEMON Wed Nov 23 11:38:42 2005
Date: 23 Nov 2005 11:38:42 +0100
From: Mail System Internal Data &lt;MAILER-DAEMON@imap.example.org&gt;
Subject: DON'T DELETE THIS MESSAGE -- FOLDER INTERNAL DATA
Message-ID: &lt;1132742322@imap.example.org&gt;
X-IMAP: 1132742306 0000000001
Status: RO

This text is part of the internal format of your mail folder, and is not
a real message.  It is created automatically by the mail system software.
If deleted, important folder data will be lost, and it will be re-created
with the data reset to initial values.
</pre>
</blockquote>

<p>As this message does not contain useful information, fetchmail is not
retrieving it. And deleting it might slow down the server if you are
keeping messages on the server, and the server would recreate it
anyways, that's why fetchmail does not bother to delete it either.</p>

<h2><a name="O16">O16. Why is the Fetchmail FAQ only available in
	ISO-216 A4 format? How do I get the FAQ in Letter format?</a></h2>

<p>All the world uses ISO-216:1975 "A4" paper except for North America.
Using A4 format reaches far more people than (formerly known as DIN A4,
from DIN&nbsp;476) format. Besides that, A4 paper <em>is</em> available in North
America.
For further information on the Letter-vs-A4 story, see:</p>
<ul><li><a href="https://www.cl.cam.ac.uk/~mgk25/iso-paper.html">Markus
	Kuhn: "International standard paper sizes"</a></li>
    <li><a
	href="http://betweenborders.com/wordsmithing/a4-vs-us-letter/">Brian
	Forte: "A4 vs US Letter"</a></li></ul>

<p>Offering the document formatted for two different paper sizes would
bloat the package beyond reason, and formatting in a way that fits A4
and Letter paper formats would be a waste of paper in most parts of the
world. For that reason, fetchmail only ships with an A4 formatted PDF
document.</p>

<p>To create a letter-sized PDF, install <a
    href="http://www.htmldoc.org/">HTMLDOC</a>, edit
<code>fetchmail-FAQ.book</code> in the source directory with your
favorite text editor, replace <samp>--size A4</samp> by <samp>--size
    letter</samp>, and type:
</p>
<pre>
make fetchmail-FAQ.pdf
</pre>

<h2><a name="O17">O17. Linux logs "TCP(fetchmail:...): Application bug, race
    in MSG_PEEK."</a></h2>
<p>That's in fact a bug in Linux kernels around the late 2.6.2X versions,
rather than fetchmail.  Fetchmail has no race bugs around MSG_PEEK,
as of version 6.3.9. The message can safely be ignored.</p>
<hr/>

<table width="100%" cellpadding="0" summary="Canned page footer">
<tr>
<td width="30%">Back to <a href="index.html">Fetchmail Home
Page</a></td>
<td width="30%" align="right">$Date$</td>
</tr>
</table>

<br clear="left"/>
<address>Eric S. Raymond <a
	href="mailto:esr@thyrsus.com">&lt;esr@thyrsus.com&gt;</a><br />
Matthias Andree</address>

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