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<title>getmail frequently-asked questions (FAQs) (version 4)</title>
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<!----><h1 id="title">getmail documentation</h1>
<p class="introduction">
This is the documentation for getmail version 4. Version 4 includes
numerous changes from version 3.x; if you are using getmail version 3,
please refer to the documentation included with that version of the
software.
</p>
<p class="about">
getmail is Copyright © 1998-2009 Charles Cazabon.
</p>
<p class="about">
getmail is licensed under the
<a href="COPYING">GNU General Public License version 2</a>
(only). If you wish to obtain a license to distribute getmail under other
terms, please contact me directly.
</p>
<h1 id="toc">Table of Contents</h1>
<ul>
<li><a href="documentation.html">getmail documentation</a></li>
<li>
<ul>
<li><a href="documentation.html#title">getmail documentation</a></li>
<li>
<ul>
<li><a href="documentation.html#features">Features</a></li>
<li><a href="documentation.html#v4differences">Differences from previous versions</a></li>
<li><a href="documentation.html#requirements">Requirements</a></li>
<li><a href="documentation.html#obtaining">Obtaining getmail</a></li>
<li><a href="documentation.html#installing">Installing getmail</a></li>
<li><a href="documentation.html#mailing-lists">getmail mailing lists</a></li>
</ul>
</li>
</ul>
</li>
<li><a href="configuration.html">getmail configuration</a></li>
<li>
<ul>
<li><a href="configuration.html#configuring">Configuring getmail</a></li>
<li>
<ul>
<li><a href="configuration.html#rcfile">Creating a getmail rc file</a></li>
</ul>
</li>
<li><a href="configuration.html#running">Running getmail</a></li>
<li>
<ul>
<li><a href="configuration.html#running-commandline-options">Commandline options</a></li>
<li><a href="configuration.html#running-mda">Using getmail as an MDA</a></li>
<li><a href="configuration.html#running-fetch">Using getmail_fetch to retrieve mail from scripts</a></li>
</ul>
</li>
</ul>
</li>
<li><a href="troubleshooting.html">getmail troubleshooting</a></li>
<li>
<ul>
<li><a href="troubleshooting.html#troubleshooting">Troubleshooting problems</a></li>
<li>
<ul>
<li><a href="troubleshooting.html#error-messages">Error messages</a></li>
<li><a href="troubleshooting.html#warning-messages">Warning messages</a></li>
<li><a href="troubleshooting.html#unexpected-behaviour">Unexpected Behaviour</a></li>
</ul>
</li>
</ul>
</li>
<li><a href="faq.html">getmail frequently-asked questions (FAQs)</a></li>
<li>
<ul>
<li><a href="faq.html#faq">Frequently-Asked Questions (FAQs)</a></li>
<li>
<ul>
<li><a href="faq.html#faq-about">About getmail</a></li>
<li>
<ul>
<li><a href="faq.html#faq-about-what">What is getmail?</a></li>
<li><a href="faq.html#faq-about-platforms">What platforms/machines does getmail run on?</a></li>
<li>
<ul>
<li><a href="faq.html#faq-about-platforms-windows">Does getmail run on MS Windows?</a></li>
<li><a href="faq.html#faq-about-platforms-mac">Does getmail run on Macintosh systems?</a></li>
<li><a href="faq.html#faq-about-platforms-unix">Does getmail require Unix/Linux?</a></li>
</ul>
</li>
<li><a href="faq.html#faq-about-support">How can I get support for getmail?</a></li>
<li><a href="faq.html#faq-about-bug">I think I found a bug! How do I report it?</a></li>
<li><a href="faq.html#faq-about-random-feature">I have a neat idea for random feature "foo" … how do I get you to implement it?</a></li>
<li><a href="faq.html#faq-about-random-feature-rejected">Why won't you implement random feature "foo"?</a></li>
<li><a href="faq.html#faq-about-virus">Does getmail support virus scanning of retrieved messages?</a></li>
<li><a href="faq.html#faq-about-spam">Does getmail support spam filtering of retrieved messages?</a></li>
<li><a href="faq.html#faq-about-ssl">Does getmail support SSL?</a></li>
<li><a href="faq.html#faq-about-rewrite">Does getmail rewrite mail headers when it retrieves mail?</a></li>
<li><a href="faq.html#faq-about-upgrade">Can I upgrade from getmail 3 to getmail 4? What about my "oldmail" files?</a></li>
<li><a href="faq.html#faq-about-why">Why did you write getmail? Why not just use fetchmail?</a></li>
</ul>
</li>
<li><a href="faq.html#faq-configuring">Configuring getmail</a></li>
<li>
<ul>
<li><a href="faq.html#faq-configuring-domain-mailbox">What is a "domain mailbox"?</a></li>
<li><a href="faq.html#faq-configuring-mta">Do I have to run sendmail or another MTA to use getmail?</a></li>
<li><a href="faq.html#faq-configuring-root">Will getmail deliver mail as root?</a></li>
<li><a href="faq.html#faq-configuring-maildir">What's a maildir?</a></li>
<li><a href="faq.html#faq-configuring-mboxrd">What's "mboxrd" format?</a></li>
<li><a href="faq.html#faq-configuring-envelope">What's this "envelope sender" and "envelope recipient" stuff?</a></li>
<li>
<ul>
<li><a href="faq.html#faq-configuring-envelope-header">Message header vs. message envelope</a></li>
<li><a href="faq.html#faq-configuring-envelope-bcc">Receiving messages without your address in the message header</a></li>
<li><a href="faq.html#faq-configuring-envelope-record">Responsibility for recording the message envelope</a></li>
<li><a href="faq.html#faq-configuring-envelope-multidrop">How this relates to domain or multidrop mailboxes</a></li>
</ul>
</li>
<li><a href="faq.html#faq-configuring-simple">This rc stuff seems complicated. Does it have to be?</a></li>
</ul>
</li>
<li><a href="faq.html#faq-how">How do I …</a></li>
<li>
<ul>
<li><a href="faq.html#faq-how-multi">How do I retrieve mail from multiple accounts?</a></li>
<li><a href="faq.html#faq-how-filter">How do I get getmail to deliver messages to different mailboxes based on …</a></li>
<li><a href="faq.html#faq-how-no-delivered-to">How do I stop getmail adding a Delivered-To: header to messages?</a></li>
<li><a href="faq.html#faq-how-no-received">How do I stop getmail adding a Received: header to messages?</a></li>
<li><a href="faq.html#faq-how-smtp">How do I make getmail deliver messages by re-injecting with SMTP?</a></li>
<li><a href="faq.html#faq-how-create-maildir">How do I create a maildir?</a></li>
<li><a href="faq.html#faq-how-create-mboxrd">How do I create an mboxrd file?</a></li>
<li><a href="faq.html#faq-how-mh">How do I make getmail deliver messages to an mh folder?</a></li>
<li><a href="faq.html#faq-how-daemon">How do I run getmail in "daemon" mode?</a></li>
<li><a href="faq.html#faq-how-maxpersession">How do I make getmail stop after retrieving X messages so that the server actually flushes deleted messages?</a></li>
<li><a href="faq.html#faq-how-hotmail">How do I make getmail retrieve mail from Hotmail?</a></li>
<li><a href="faq.html#faq-how-to">I'm using getmail. How do I make it …</a></li>
<li>
<ul>
<li><a href="faq.html#faq-how-to-tempstop">I'm running getmail from cron. How do I temporarily stop it?</a></li>
<li><a href="faq.html#faq-how-to-mutex">How do I stop multiple instances of getmail from running at the same time?</a></li>
</ul>
</li>
</ul>
</li>
<li><a href="faq.html#faq-integrating">Using getmail with other software</a></li>
<li>
<ul>
<li><a href="faq.html#faq-integrating-spamassassin">How do I use SpamAssassin with getmail?</a></li>
<li><a href="faq.html#faq-integrating-clamav">How do I use ClamAV with getmail?</a></li>
<li>
<ul>
<li><a href="faq.html#faq-integrating-clamav-prettier">Getting prettier output from ClamAV</a></li>
</ul>
</li>
<li><a href="faq.html#faq-integrating-fprot">How do I use F-Prot with getmail?</a></li>
<li><a href="faq.html#faq-integrating-procmail">How do I use procmail with getmail?</a></li>
<li><a href="faq.html#faq-integrating-maildrop">How do I use maildrop with getmail?</a></li>
<li><a href="faq.html#faq-integrating-tmda">How do I use TMDA with getmail?</a></li>
<li>
<ul>
<li><a href="faq.html#faq-integrating-gmail">How can I get Gmail labels with getmail?</a></li>
</ul>
</li>
</ul>
</li>
<li><a href="faq.html#faq-notabug">I think I found this bug in getmail …</a></li>
<li>
<ul>
<li><a href="faq.html#faq-notabug-gmail-bug">getmail doesn't download all my mail from Gmail …</a></li>
<li><a href="faq.html#faq-notabug-futurewarning">FutureWarning: %u/%o/%x/%X of negative int will return a signed string in Python 2.4 and up</a></li>
<li><a href="faq.html#faq-notabug-fsync">AttributeError: 'module' object has no attribute 'fsync'</a></li>
<li><a href="faq.html#faq-notabug-brokenpopserver">operation error (SimplePOP3Retriever: [...] does not uniquely identify messages [...] see documentation or use BrokenUIDLPOP3Retriever instead</a></li>
<li><a href="faq.html#faq-notabug-osx-realloc">MemoryError on OS X</a></li>
<li><a href="faq.html#faq-notabug-memory">MemoryError when using IMAP</a></li>
</ul>
</li>
</ul>
</li>
</ul>
</li>
</ul>
<!-- ********************************************************************** -->
<h1 id="faq">Frequently-Asked Questions (FAQs)</h1>
<p>
The following questions about getmail are answered more-or-less frequently.
Please also read the
<a href="troubleshooting.html#unexpected-behaviour">unexpected behaviour section</a>
of the
<a href="troubleshooting.html">troubleshooting document</a>.
</p>
<!-- ********************************************************************** -->
<h2 id="faq-about">About getmail</h2>
<h3 id="faq-about-what">What is getmail?</h3>
<p>
getmail is a mail retriever with support for POP3, POP3-over-SSL, IMAP4,
IMAP4-over-SSL, and SDPS mail accounts. It supports normal single-user mail
accounts and multidrop (domain) mailboxes. getmail is written in Python, and
licensed under the
<a href="COPYING">GNU General Public License version 2</a>.
</p>
<h3 id="faq-about-platforms">What platforms/machines does getmail run on?</h3>
<p>
getmail runs on basically any platform. It's designed to, and written
in a language that helps to maintain cross-platform compatibility.
getmail is known to run on the following platforms:
</p>
<ul>
<li>Linux-based GNU systems (all distributions)</li>
<li>HURD-based GNU systems</li>
<li>FreeBSD</li>
<li>OpenBSD</li>
<li>NetBSD</li>
<li>HP/UX</li>
<li>Sun Solaris</li>
<li>IBM AIX</li>
<li>Digital/Compaq Tru64 (a.k.a OSF/1) UNIX</li>
<li>SGI Irix</li>
<li>other commercial Unices</li>
<li>Digital VMS / OpenVMS</li>
<li>BeOS</li>
<li>Amiga OS</li>
<li>OS/2</li>
<li>Cygwin on Windows</li>
<li>Macintosh OS X</li>
<li>Macintosh OS 9</li>
</ul>
<p>
But getmail will also run on other, less common platforms. The only real
requirement is that Python run on that platform, and porting Python is
generally very easy.
</p>
<h4 id="faq-about-platforms-windows">Does getmail run on MS Windows?</h4>
<p>
Yes, under the free <a href="http://cygwin.com/">Cygwin</a> package.
Running recent versions of Python under Cygwin requires a process known
as "rebasing" your Cygwin installation; you can find details
in
<a href="http://mail.python.org/pipermail/python-dev/2003-July/036932.html">this Python developers' mailing list message</a>.
</p>
<h4 id="faq-about-platforms-mac">Does getmail run on Macintosh systems?</h4>
<p>
<a href="#faq-about-platforms">Yes.</a>
</p>
<h4 id="faq-about-platforms-unix">Does getmail require Unix/Linux?</h4>
<p>
<a href="#faq-about-platforms">No.</a>
</p>
<h3 id="faq-about-support">How can I get support for getmail?</h3>
<p>
getmail is
<a href="http://www.fsf.org/">Free Software</a>.
As such, it comes with no warranty. However, I will do my best to support
getmail on a voluntary basis through the
<a href="documentation.html#mailing-list-users">getmail mailing list</a>.
</p>
<p>
If you are using getmail in a commercial or other environment where problems
cost money, consider contacting me privately for commercial support, by
emailing <charlesc-getmail-support @ pyropus.ca>
</p>
<p>
If you have questions about getmail, the first step is to read the
<a href="documentation.html">documentation</a>,
and the remainder of the Frequently Asked Questions. If your question isn't
answered there, search the
<a href="documentation.html#mailing-list-users-archive">getmail mailing list archives</a>.
</p>
<p>
If you still haven't found an answer to your question, please subscribe to
the
<a href="documentation.html#mailing-list-users">getmail users' mailing list</a>
by sending a blank email to <getmail-subscribe @
lists.pyropus.ca>. If you post your question there, I will see it.
As an additional bonus, your question may be answered by another member of
the list.
</p>
<h3 id="faq-about-bug">I think I found a bug! How do I report it?</h3>
<p class="important">
First, make sure that you are running the latest version. You can always
find what is the latest version by checking this page at the original
web site:
<br />
<a href="http://pyropus.ca/software/getmail/">http://pyropus.ca/software/getmail/</a>.
<br />
If you running an older version of the software, chances are whatever bug
you may have found has already been fixed.
</p>
<p>
Ideally, you should join the
<a href="documentation.html#mailing-list-users">mailing list</a>
and send your bug report there. You should include the following
information:
</p>
<ul>
<li>getmail version</li>
<li>Python version</li>
<li>any error message which getmail displayed</li>
<li>
the output from running getmail with your normal options plus
<span class="sample">--dump</span>
</li>
<li>
if your problem is getmail not determining the proper local recipient,
please include the output of running getmail with your normal options
plus
<span class="sample">--trace</span>,
showing the retrieval of
<strong>one</strong>
problematic message.
</li>
</ul>
<p>
If you absolutely cannot sign up for the mailing list, send the report to me
directly at
<charlesc-getmail-bugs @ pyropus.ca>.
I may not be able to respond to all reports privately, but I will
try to address any bugs I find out about this way.
</p>
<h3 id="faq-about-random-feature">I have a neat idea for random feature "foo" … how do I get you to implement it?</h3>
<p>
Follow the same instructions as for reporting bugs above — yes, that
means I would prefer you submit your idea to the getmail users' mailing list.
That will lead to a useful discussion if your feature has not been proposed
before.
</p>
<h3 id="faq-about-random-feature-rejected">Why won't you implement random feature "foo"?</h3>
<p>
Every line of code added to getmail has a certain cost. Every feature
added requires code, documentation, and support. Adding features increases
the complexity of the software, confuses users, and leads to higher support
costs. I therefore weigh features very carefully as a cost-versus-benefit
tradeoff before deciding whether to add them.
</p>
<p>
Some users are confused by this. They think that a feature you don't use
has no cost, and therefore if it has any value to anyone, it should be
added. That simply isn't the case; the costs of an unused feature are
simply borne by others, including me.
</p>
<p>
If you have asked me to add some feature, and I've said no, this may be
the reason. Other possibilities include me simply not having had sufficient
time to implement it yet.
</p>
<h3 id="faq-about-virus">Does getmail support virus scanning of retrieved messages?</h3>
<p>
Yes. You can use getmail message filtering options to do this with an
external virus scanning program, or invoke your virus scanning program
during delivery with getmail's support for external MDAs.
</p>
<p>
Also see the FAQ about
<a href="#faq-integrating-clamav">using getmail with the ClamAV program</a>.
</p>
<h3 id="faq-about-spam">Does getmail support spam filtering of retrieved messages?</h3>
<p>
Yes. You can use getmail message filtering options to do this with an
external spam filtering program, or invoke your spam filtering program
during delivery with getmail's support for external MDAs.
</p>
<p>
Also see the FAQ about
<a href="#faq-integrating-spamassassin">using getmail with the SpamAssassin program</a>.
</p>
<h3 id="faq-about-ssl">Does getmail support SSL?</h3>
<p>
Yes. getmail has built in support for POP3-over-SSL and IMAP4-over-SSL.
</p>
<h3 id="faq-about-rewrite">Does getmail rewrite mail headers when it retrieves mail?</h3>
<p>
No. Rewriting message header fields is bad for many reasons; the biggest
problem is that it causes a loss of critical technical information necessary
to track down many mail problems. getmail will add a new
<span class="file">Received:</span>
header field and a new
<span class="file">Delivered-To:</span>
header field, but does not rewrite existing headers. You can disable the
creation of these header fields.
</p>
<h3 id="faq-about-upgrade">Can I upgrade from getmail 3 to getmail 4? What about my "oldmail" files?</h3>
<p>
Yes. getmail version 4 uses exactly the same
<span class="file">oldmail-<span class="meta">server</span>-<span class="meta">port</span>-<span class="meta">username</span></span>
naming convention for its oldmail files. The only difference is that
version 4 escapes a couple of additional characters in this string so that
it is truly cross-platform compatible. If you upgrade from version 3 to
version 4, getmail will still remember which messages you've already
retrieved.
</p>
<p>
To upgrade, do the following:
</p>
<ol>
<li>
Rename your old getmail rc file, creating a new file in
<span class="file">~/.getmail/getmailrc</span>.
</li>
<li>
Create a new
<span class="file">[options]</span>
section, containing the appropriate values from your version 3 rc file
<span class="file">[defaults]</span>
section.
</li>
<li>
Create a new
<span class="file">[retriever]</span>
section, using your previous server configuration values in a new
<span class="file">type = SimplePOP3Retriever</span>
or
<span class="file">type = MultidropPOP3Retriever</span>
as appropriate.
</li>
<li>
Create a new
<span class="file">[destination]</span>
section, using your previous destination path values in a new
<span class="file">type = Maildir</span>,
<span class="file">type = Mboxrd</span>,
<span class="file">type = MDA_external</span>,
or
<span class="file">type = MultiSorter</span>
destination as appropriate.
</li>
<li>
If you were retrieving messages from multiple mail accounts in a
single version 3 getmail rc file, split them up into one account per
version 4 rc file.
</li>
</ol>
<p>
That's it.
</p>
<h3 id="faq-about-why">Why did you write getmail? Why not just use fetchmail?</h3>
<p>
Short answer: … well, the short answer is mostly unprintable.
The long answer is … well, long:
</p>
<p>
I do not like some of the design choices which were made with fetchmail.
getmail does things a little differently, and for my purposes, better. In
addition, most people find getmail easier to configure and use than
fetchmail. Perhaps most importantly, getmail goes to great lengths to
ensure that mail is never lost, while fetchmail (in its default
configuration) frequently loses mail, causes mail loops, bounces legitimate
messages, and causes many other problems.
</p>
<p>
When people have pointed out problems in fetchmail's design and
implementation, it's maintainer has frequently ignored them, or (worse yet)
gone in the completely wrong direction in the name of "fixing" the
problems. For instance, fetchmail's configuration file syntax has been
criticized as being needlessly difficult to write; instead of cleaning up
the syntax, the maintainer instead included a GUI configuration-file-writing
program, leading to
<a href="http://www.crackmonkey.org/pipermail/crackmonkey/2003q3/037098.html">comments</a>
like:
</p>
<blockquote cite="http://www.crackmonkey.org/pipermail/crackmonkey/2003q3/037098.html">
<p>
The punchline is that fetchmail sucks, even if it does have
giddily-engineered whizbang configurator apps.
</p>
</blockquote>
<p>
As an example,
<a href="http://cr.yp.to/djb.html">Dan Bernstein</a>,
author of
<a href="http://cr.yp.to/qmail.html">qmail</a>
and
<a href="http://cr.yp.to/software.html">other software packages</a>,
once noted to the qmail list:
</p>
<blockquote cite="http://www.mail-archive.com/qmail@id.wustl.edu/msg06997.html">
<p>
Last night, root@xxxxxxxxxxxxxxxxx reinjected thirty old messages from
various authors to qmail@xxxxxxxxxxxxxx
</p>
<p>
This sort of idiocy happens much more often than most subscribers know,
thanks to a broken piece of software by Eric Raymond called fetchmail.
Fortunately, qmail and ezmlm have loop-prevention mechanisms that stop
these messages before they are distributed to subscribers. The messages
end up bouncing to the wrong place, thanks to another fetchmail bug, but
at least the mailing list is protected.
</p>
<p>
--D. J. Bernstein
</p>
</blockquote>
<p>
The maintainer also ignored dozens of complaints about fetchmail's
behaviour, stating (by fiat) that fetchmail was bug-free and had entered
"maintenance mode", allowing him to ignore further bug reports.
</p>
<p>
fetchmail's default configuration values frequently cause lost or
misdirected mail, and seem to be chosen to cause maximum pain and
inconvenience. From fetchmail's to-do file (emphasis mine):
</p>
<blockquote>
<p>
<em>Maybe</em> refuse multidrop configuration unless
"envelope" is _explicitly_ configured
…
This would prevent a significant class of shoot-self-in-foot
problems.
</p>
<p>
<em>perhaps</em> treat a delivery as "temporarily failed"
…
This is so you don't lose mail if you configure the wrong envelope
header.
</p>
</blockquote>
<p>
fetchmail is famous for mangling messages it retrieves, rather than
leaving them alone as a mail-handling program should. getmail will add
trace information to messages (so you can see what happened, and when),
but will otherwise leave message content alone.
</p>
<p>
In addition, fetchmail has a long history of security problems:
</p>
<ul>
<li>
versions released before 20 June 2001 contain a buffer overflow, which
can be remotely exploited (see
<a href="http://www.securityfocus.com/bid/2877">www.securityfocus.com/bid/2877</a>
for details). getmail is not vulnerable to buffer overflows, because
buffers in Python are dynamically sized.
</li>
<li>
Another remotely-exploitable security hole discovered in fetchmail in June 2002;
<a href="http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2002-0146">
versions prior to 5.9.10 (released in June 2002) are exploitable
</a>.
</li>
<li>
Reading fetchmail's UPDATES file, it appears that another security
problem was fixed in 5.9.12, where a server could crash fetchmail on
64-bit platforms. Also worrying is a mention that it includes a fix for
"password shrouding".
</li>
<li>
Another remotely-exploitable security hole in fetchmail discovered in
September 2002;
<a href="http://security.e-matters.de/advisories/032002.html">
this hole
</a>
lets an attacker run arbitrary code on the victim's computer.
</li>
<li>
Another remotely-exploitable security hole in fetchmail discovered in
December 2002; once again, a remote attacker can run arbitrary code on
the machine running fetchmail in its default configuration. See
<a href="http://security.e-matters.de/advisories/052002.html">
this advisory
</a>
for details.
</li>
<li>
January 2003:
<a href="http://cve.mitre.org/cgi-bin/cvename.cgi?name=3DCAN-2002-1365">
More buffer overflows in fetchmail let attackers run arbitrary code
</a>.
</li>
<li>
October 2003:
<a href="http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2003-0792">
Anyone can cause fetchmail to crash by sending you a message
</a>.
Other problems are
<a href="http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2003-0790">
here
</a>,
and
<a href="http://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=fetchmail">
I might have missed some
</a>.
</li>
<li>
Just in case you thought fetchmail was all better now, there's still
new security problems being discovered in it. In December, 2005,
it was revealed that
<a href="http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2005-4348">anyone can send a fetchmail multidrop user a message that causes fetchmail to crash</a>.
</li>
</ul>
<p>
In July, 2004, it was noted that there may be at least 2 unfixed denial-of-service attacks,
2 unfixed remote-code-execution, 2 unfixed remote-user-access, and 3 unfixed
remote-shell attacks against fetchmail. See
<a href="http://www.mail-archive.com/euglug@euglug.org/msg00971.html">http://www.mail-archive.com/euglug@euglug.org/msg00971.html</a>
for details
</p>
<p>
I've given up even trying to stay abreast of the various security holes in
fetchmail, but others have noted continuing problems, including:
</p>
<ul>
<li>
<a href="http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2005-2335">another
arbitrary code execution vulnerability</a>
announced on 21 July 2005.
</li>
</ul>
<p>
The fetchmail authors' boneheaded decision to create a configuration-file
GUI editor (rather than actually giving fetchmail a sane configuration
syntax) also came back to bite them in the ass: in October 2005, it
became known that fetchmailconf created its files in such a way that
<a href="http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2005-3088">users' passwords could be read</a> during file creation.
</p>
<p>
Addendum, January 2007: since I wrote the above, the following new security
problems have been discovered in fetchmail:
</p>
<ul>
<li><a href="http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2005-4348">CVE-2005-4348</a> - anyone can crash fetchmail by sending messages without headers</li>
<li><a href="http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-0321">CVE-2006-0321</a> - anyone can crash fetchmail by sending a message that fetchmail tries to bounce</li>
<li><a href="http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-5867">CVE-2006-5867</a> - fetchmail can transmit passwords in plaintext even if the user has configured it not to</li>
<li><a href="http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-5974">CVE-2006-5974</a> - anyone can cause fetchmail to crash by triggering certain error code paths</li>
</ul>
<p>
But don't just take my word for it; see
<a href="http://docs.freebsd.org/cgi/mid.cgi?200102172349.QAA11724">
http://docs.freebsd.org/cgi/mid.cgi?200102172349.QAA11724
</a>
and
<a href="http://web.archive.org/web/20080621090439/http://esr.1accesshost.com/">http://esr.1accesshost.com/</a> (note:
went offline sometime in 2009 or 2010; the content is still available at
http://web.archive.org/web/20080621090439/http://esr.1accesshost.com/ ).
</p>
<p>
getmail users have not had to worry about any of these security holes or
design and implementation errors.
</p>
<!-- ********************************************************************** -->
<h2 id="faq-configuring">Configuring getmail</h2>
<h3 id="faq-configuring-domain-mailbox">What is a "domain mailbox"?</h3>
<p>
A domain (or multidrop) mailbox is a POP3 mailbox which receives mail for
all users in a given domain. Normal mailboxes contain mail for a single
user (like
<span class="file">jason@myisp.co.uk</span>);
some Internet Service Providers which provide webhosting or other services
will provide a POP3 mailbox which receives mail for all addresses in a given
domain (i.e. mail for
<span class="file">service@smallcompany.net</span>,
<span class="file">sales@smallcompany.net</span>,
and indeed anything
<span class="file">@smallcompany.net</span>
ends up in the same POP3 mailbox).
</p>
<p>
getmail provides a method of retrieving mail from a domain mailbox and
distributing it among the various users automatically. The retriever
classes
<a href="configuration.html#retriever-multidroppop3">MultidropPOP3Retriever</a>,
<a href="configuration.html#retriever-multidroppop3ssl">MultidropPOP3SSLRetriever</a>,
<a href="configuration.html#retriever-multidropsdps">MultidropSDPSRetriever</a>,
<a href="configuration.html#retriever-multidropimap">MultidropIMAPRetriever</a>,
and
<a href="configuration.html#retriever-multidropimapssl">MultidropIMAPSSLRetriever</a>
provide this capability.
</p>
<p>
See the
<a href="configuration.html#conf-retriever-multidrop">documentation on the
<span class="file">[retriever]</span>
section</a>
for details of what the requirements for a multidrop mailbox are.
getmail user Matthias Andree also has a
<a href="http://www.dt.e-technik.uni-dortmund.de/~ma/mail/multidrop">web page about multidrop mailboxes</a>.
</p>
<h3 id="faq-configuring-mta">Do I have to run sendmail or another MTA to use getmail?</h3>
<p>
No. getmail delivers directly to maildirs, mboxrd files, or via arbitrary
MDAs, and never injects mail via SMTP, so no MTA is necessary.
</p>
<h3 id="faq-configuring-root">Will getmail deliver mail as root?</h3>
<p>
No. When run as the root user on a Unix-like system, getmail drops
privileges (switches to an unprivileged group and user id) before delivering
to maildirs or mboxrd files. You can specify the user explicitly, or
let getmail use the owner of the maildir or mboxrd file.
</p>
<p>
If getmail attempts to deliver mail and finds it has UID 0 or GID 0, it
will refuse the delivery and print an error message.
</p>
<h3 id="faq-configuring-maildir">What's a maildir?</h3>
<p>
A maildir is a mail storage format invented by D. J. Bernstein (author of
qmail) that requires no file locking to deliver to safely and reliably, even
over NFS. getmail natively supports delivery to maildirs.
</p>
<p>
See
<a href="http://qmail.org/man/man5/maildir.html">http://qmail.org/man/man5/maildir.html</a>
and
<a href="http://cr.yp.to/proto/maildir.html">http://cr.yp.to/proto/maildir.html</a>
for details.
</p>
<h3 id="faq-configuring-mboxrd">What's "mboxrd" format?</h3>
<p>
There are various sub-types of the mbox mail storage format. mboxrd is
the most reliable of them, though (like all mbox types) it still relies
on file locking and is therefore more easily corrupted than maildir format.
In particular, using mbox files with multiple writers over NFS can be
problematic.
</p>
<p>
For details on the differences between the various mbox sub-types, see
<a href="http://qmail.org/man/man5/mbox.html">http://qmail.org/man/man5/mbox.html</a>.
</p>
<h3 id="faq-configuring-envelope">What's this "envelope sender" and "envelope recipient" stuff?</h3>
<p>
The "envelope" of an email message is "message
metadata"; that is, the message is information, and the envelope is
information about the message (information about other information).
Knowing this is critical to understanding what a domain or multidrop mailbox
is, how it works, and what getmail can do for you.
</p>
<p>
<a href="http://cr.yp.to/smtp/mail.html">Others have tried to explain this</a>
with varying degrees of success. I'll use the standard analogy of normal
postal (i.e. non-electronic) mail:
</p>
<h4 id="faq-configuring-envelope-header">Message header vs. message envelope</h4>
<p>
When you receive a letter (a reply from the customer-disservice department
of your telephone company, say) it arrives in an envelope. You tear it
open, remove the letter, and read it. At the top of the letter is the
telephone company's return address, followed by the date the letter was
written. Your name and mailing address follow that, and then the remainder
of the letter.
</p>
<p>
The important thing to keep in mind is that the contents of the letter
(including the addresses just discussed) are never looked at by the post
office. If they can't deliver the letter (your mailing address on the
envelope got smudged in the rain), they'll return it to the address listed
in the top-left corner of the envelope. They don't check to make sure that
the address listed there is the same as the one listed at the top of the
letter. Similarly, when they can successfully deliver it, they don't check
to make sure that the recipient name and address on the envelope matches the
one listed on the letter between the date and the salutation.
</p>
<p>
The message header fields
<span class="file">From:</span>
and
<span class="file">Resent-from:</span>
are equivalent to the block of address information at the top of the letter;
it usually contains the name and address of the sender of the message,
but it is never actually used in the delivery of the message.
Similarly, the
<span class="file">To:</span>,
<span class="file">cc:</span>,
<span class="file">Resent-to:</span>,
<span class="file">and Resent-cc:</span>
header fields are the equivalent of the block of address information between
the date and the salutation on the letter; they usually contain the names
and addresses of the intended recipients of the message, but they too are
not used in the delivery of the message.
</p>
<h4 id="faq-configuring-envelope-bcc">Receiving messages without your address in the message header</h4>
<p>
You might open an envelope addressed to you and find that the letter inside
makes no mention of your name. Your name and address don't appear anywhere
in the letter, but it was still successfully delivered to you based on the
envelope information. There's nothing strange about this. If someone else
opens your mail for you, discards the envelopes, and places the contents
in your in-basket, you might wonder how some of it ended up there, because
there's nothing to connect you with the message contents.
</p>
<p>
Email is exactly like this. Each message has two parts, the message
contents, and the message envelope. The message contents include the
message header, and the message body. The message envelope is made up of
exactly one envelope sender address (which can be empty) and one or more
envelope recipient addresses. If the message cannot be delivered for any
reason, and the envelope sender address is
<strong>not</strong>
empty, the message
<strong>must</strong>
be returned to the envelope sender address by the mail transfer agent (MTA)
which last accepted responsibility for delivering the message.
These notifications are known as "bounce messages" or
sometimes as "non-delivery notifications". Bounce messages are
sent using the empty envelope return path, to prevent mail loops from
occurring when a bounce message itself cannot be delivered.
</p>
<p>
Confusion often arises among novice users about the difference between the
message header and the message envelope; they seem to believe that they
are not independant. This appears to be an artifact of their use of
simple-minded GUI mail user agents (MUAs) that do not allow them to set
the envelopes of their messages explicitly, but instead simply use the
contents of the From: header field as the envelope sender address, and
any addresses found in
<span class="file">To:</span>,
<span class="file">cc:</span>,
and
<span class="file">bcc:</span>
header fields as the envelope recipient addresses. While these are
sensible
<em>as default values</em>,
more powerful MUAs allow the user to override this choice.
</p>
<h4 id="faq-configuring-envelope-record">Responsibility for recording the message envelope</h4>
<p>
The last MTA to receive a message (usually the one running on the POP or
IMAP server where you retrieve your mail from) essentially acts as your
correspondence secretary, accepting your mail from the postman, opening it,
and placing it into your in-basket. Note that this would normally destroy
the important information contained in the message envelope. To prevent
this loss of information, this MTA is supposed to copy the information from
the envelope into new fields in the header of the message content, as if
your secretrary copied the sender and recipient addresses onto the back of
your letters in felt pen. Unfortunately, some MTAs do not always do this
properly, and envelope information can then be lost. When this happens,
it makes dealing with certain types of mail messages problematic:
</p>
<ul>
<li>
bcc'd messages (bcc stands for blind carbon copy), where you are an
envelope recipient, but your address does not appear in the message
content (i.e., your address does not appear in a
<span class="file">To:</span>,
<span class="file">cc:</span>,
or similar message header field). With bcc'd messages, the
<span class="file">From:</span>
header field contains the name and address of the author of the message,
and the
<span class="file">To:</span>
and
<span class="file">cc:</span>
header fields contain the names and addresses of the other, non-blind
recipients of the message.
</li>
<li>
mailing list messages, where you are an envelope recipient, but your
address does not appear in the message content (i.e., your address does
not appear in a
<span class="file">To:</span>,
<span class="file">cc:</span>,
or similar message header field). Mailing list messages have the
envelope sender address set to the mailing list manager (so that it
can monitor "bad" list addresses for bounces), while the
<span class="file">From:</span>
header field contains the name and address of the author of the
message. The envelope recipient addresses of mailing list messages
are the addresses of the list subscribers, while the
<span class="file">To:</span>
header field usually contains the address of the mailing list.
</li>
<li>
other, less common cases.
</li>
</ul>
<p>
MTAs are supposed to record the envelope sender address by placing it into a
new
<span class="file">Return-Path:</span>
header field at the top of the message. They should then record the
envelope recipient address(es) in another new header field; sometimes this
header field is named
<span class="file">Delivered-To:</span>,
but it can also be
<span class="file">Envelope-To:</span>
or one of a few other names.
</p>
<h4 id="faq-configuring-envelope-multidrop">How this relates to domain or multidrop mailboxes</h4>
<p>
A domain or multidrop mailbox is one which receives mail for multiple email
addresses (commonly all addresses in a given domain). If you do not want
all of this mail to go to one person, you need to know who the messages
were originally addressed to after retrieving them from the POP/IMAP
multidrop mailbox. You
<strong>cannot</strong>
do this by looking at the
<span class="file">To:</span>,
<span class="file">cc:</span>,
or other informational message header fields, because they do not actually
reflect the message envelope at the time of delivery. Instead, you have
to reconstruct the envelope information from the message header fields
which the MTA on the server used to record it at the time of delivery.
</p>
<p>
If the final MTA does not record the message envelope (the envelope sender,
and all envelope recipient addresses in the domain mailbox the message was
sent to), then
<em>mail will be lost or misdirected
<strong>regardless</strong>
of which software you use to access the mailbox</em>.
The mailbox cannot actually be said to be a domain mailbox in this case; the
defining characteristic of a domain mailbox is that it records the envelope
correctly. The configuration of the MTA running on the server needs to be
fixed so that the envelope is properly recorded for every message it
receives.
</p>
<h3 id="faq-configuring-simple">This rc stuff seems complicated. Does it have to be?</h3>
<p>
The configuration file format is actually very simple; you don't need
to worry about most of it if you're not interested in using those features.
The simplest and most common getmail rc file configuration will be for
users who want to retrieve all mail from a single-user POP3 mailbox,
deliver those messages to a maildir or mbox file, and delete the mail from
the server. For maildir, that configuration is:
</p>
<pre class="example">
[options]
delete = True
[retriever]
type = SimplePOP3Retriever
server = my-pop3-servername
username = my-pop3-username
password = my-pop3-password
[destination]
type = Maildir
path = ~/Maildir/
</pre>
<p>
For an mbox file, that configuration is:
</p>
<pre class="example">
[options]
delete = True
[retriever]
type = SimplePOP3Retriever
server = my-pop3-servername
username = my-pop3-username
password = my-pop3-password
[destination]
type = Mboxrd
path = ~/inbox
</pre>
<!-- ********************************************************************** -->
<h2 id="faq-how">How do I …</h2>
<h3 id="faq-how-multi">How do I retrieve mail from multiple accounts?</h3>
<p>
Create a separate getmail rc file for each account, and run getmail with
multiple
<span class="file">--rcfile</span>
options.
</p>
<p>
Of course, it's really easy to script this for a large number of
<span class="file">rc-*</span>
files. You might create a script in
<span class="file">$HOME/bin/run-getmail.sh</span>
containing:
</p>
<pre class="example">
#!/bin/sh
set -e
cd /path/to/my-rc-directory
rcfiles=""
for file in rc-* ; do
rcfiles="$rcfiles --rcfile $file"
done
exec /path/to/getmail $rcfiles $@
</pre>
<p>
See any beginner's tutorial on Unix shell scripting for details.
</p>
<h3 id="faq-how-filter">How do I get getmail to deliver messages to different mailboxes based on …</h3>
<p>
If you want getmail to sort messages based on who they're from, or what address appears in the
<span class="file">To:</span>
or
<span class="file">cc:</span>
header fields, or based on the
<span class="file">Subject:</span>
field contents, or anything like that, pick a filtering MDA
(like maildrop or procmail), and call it from a getmail
<a href="configuration.html#destination-mdaexternal"><span class="file">MDA_external</span></a>
destination.
</p>
<h3 id="faq-how-no-delivered-to">How do I stop getmail adding a Delivered-To: header to messages?</h3>
<p>
Use the
<a href="configuration.html#conf-options">delivered_to</a>
<span class="file">[options]</span>
parameter.
</p>
<h3 id="faq-how-no-received">How do I stop getmail adding a Received: header to messages?</h3>
<p>
Use the
<a href="configuration.html#conf-options">received</a>
<span class="file">[options]</span>
parameter.
</p>
<h3 id="faq-how-smtp">How do I make getmail deliver messages by re-injecting with SMTP?</h3>
<p>
You don't need to. getmail can deliver to maildirs, mboxrd files, or
through arbitrary external MDAs.
</p>
<p>
If you still think you need to, you can use getmail's
<a href="configuration.html#destination-mdaexternal">external MDA support</a>
to do so.
</p>
<h3 id="faq-how-create-maildir">How do I create a maildir?</h3>
<p>
Use the
<span class="file">maildirmake</span>
command, if you have it installed. Otherwise, run the following command
from your shell:
</p>
<pre class="example">
$ mkdir -p /path/to/Maildir/{cur,new,tmp}
</pre>
<p>
Some other maildir-aware programs ship with their own maildir-creation
programs; you can use those, or make the above shell command a shellscript
or alias if you like.
</p>
<h3 id="faq-how-create-mboxrd">How do I create an mboxrd file?</h3>
<p>
Create a completely empty (i.e. zero bytes long) file via your favourite
method. The standard utility
<span class="file">touch</span>
is commonly used:
</p>
<pre class="example">
$ touch /path/to/mboxrd
</pre>
<h3 id="faq-how-mh">How do I make getmail deliver messages to an mh folder?</h3>
<p>
<a href="http://www.ics.uci.edu/~mh/">mh</a>
clients (and
<a href="http://www.nongnu.org/nmh/">nmh</a>,
or "new mh" clients)
include a command for delivering a message into your mh folder. In nmh,
this command is called
<span class="file">rcvstore</span>.
You use it as an external message delivery agent (MDA) with getmail's
<a href="configuration.html#destination-mdaexternal">MDA_external</a>
destination. Ensure your
<span class="file">$HOME/.mh_profile</span>
file is configured properly; getmail user Frankye Fattarelli suggests a
line like the following is necessary to indicate the path to your mh
mail root:
</p>
<pre class="example">
Path: Mail
</pre>
<p>
Then use MDA_external like this (which, after adjusting the path of the
command to reflect your mh/nmh installation, should work with either mh or
nmh):
</p>
<pre class="example">
[destination]
type = MDA_external
path = /usr/local/libexec/nmh/rcvstore
arguments = ("+inbox", )
</pre>
<p>
Thanks to Frankye Fattarelli for contributing this answer.
</p>
<h3 id="faq-how-daemon">How do I run getmail in "daemon" mode?</h3>
<p>
Use your system's cron utility to run getmail periodically if you wish to
have mail retrieved automatically at intervals. This is precisely what cron
is designed to do; there's no need to add special code to getmail to do
this.
</p>
<p>
With a reasonably standard system
<span class="file">cron</span>
utility, a
<span class="file">crontab(5)</span>
entry like the following will make getmail retrieve mail every hour:
</p>
<pre class="example">
0 * * * * /usr/local/bin/getmail --quiet
</pre>
<h3 id="faq-how-maxpersession">How do I make getmail stop after retrieving X messages so that the server actually flushes deleted messages?</h3>
<p>
Use the
<a href="configuration.html#conf-options"><span class="file">max_messages_per_session</span></a>
option to limit the number of messages getmail will process in a single
session. Some users with flaky servers use this option to reduce the
chances of seeing messages more than once if the server dies in mid-session.
</p>
<h3 id="faq-how-hotmail">How do I make getmail retrieve mail from Hotmail?</h3>
<p>
Well, you could write a retriever that speaks Hotmail's proprietary,
undocumented, and unsupported access protocol (or pay me to write one),
or simply set up the POP3 proxy from the
<a href="http://httpmail.sourceforge.net/">httpmail</a>
package, and have getmail retrieve mail from that POP3 proxy.
</p>
<h3 id="faq-how-to">I'm using getmail. How do I make it …</h3>
<p>
These are supplementary questions I occasionally see about doing various
things to enhance a
<span class="file">getmail</span>
setup. The solution to many of them is to use a standard Unix technique
of some sort to make the system behave in a certain manner, or otherwise
change the behaviour of something that's actually outside of
<span class="file">getmail</span>
proper.
</p>
<h4 id="faq-how-to-tempstop">I'm running getmail from cron. How do I temporarily stop it?</h4>
<p>
Some people ask about temporarily stopping
<span class="file">getmail</span>
from running from a
<span class="file">cron</span>
job, possibly because the mail server is down and they don't want to see
the warnings
<span class="file">cron</span>
mails them.
</p>
<p>
The easiest method is to comment out
<span class="file">getmail</span>
from your
<span class="file">crontab</span>
file:
</p>
<ol>
<li>
Run
<pre class="example">$ crontab -e</pre>
to edit your
<span class="file">crontab</span>
file.
</li>
<li>
Place a # (pound) character at the start of the line containing the call
to
<span class="file">getmail</span>.
</li>
<li>
Save the changed file.
</li>
</ol>
<p>
When you want to re-enable getmail, edit the file again and un-do the
above change.
</p>
<p>
If you need to do this on a regular basis, you can instead use a
"flag file" to tell the system whether or not to run
<span class="file">getmail</span>:
</p>
<p>
Change your
<span class="file">cron</span>
job or shellscript that normally launches
<span class="file">getmail</span>
to check for the presence of a certain file first, and have it not run
<span class="file">getmail</span>
if that file is present. For example, your
<span class="file">crontab</span>
entry could be changed to do this:
</p>
<pre class="example">
[ -f ~/.getmail/do-not-run ] || /path/to/getmail
</pre>
<p>
When you don't want getmail to run,
<span class="file">touch</span>
that file:
</p>
<pre class="example">
$ touch ~/.getmail/do-not-run
</pre>
<p>
When you want getmail to run again, delete it:
</p>
<pre class="example">
$ rm -f ~/.getmail/do-not-run
</pre>
<p>
This is even safe for scripting, as creating and removing the file are
atomic operations under Unix.
</p>
<h4 id="faq-how-to-mutex">How do I stop multiple instances of getmail from running at the same time?</h4>
<p>
getmail has no problems running multiple instances in parallel, though you
shouldn't attempt to use the same getmail rc file from two different
instances at the same time. If you need to prevent two instances of getmail
from running simultaneously, use any standard Unix method of providing a
mutex for this purpose. One example would be to run getmail under a
program like
<span class="file">setlock</span>
(part of the
<a href="http://cr.yp.to/daemontools.html"><span class="file">daemontools</span></a>
package). Change your script or
<span class="file">crontab</span>
file to invoke getmail like this:
</p>
<pre class="example">
/path/to/setlock -n /path/to/lockfile /path/to/getmail [getmail options]
</pre>
<p>
There are other programs that provide functionality similar to
<span class="file">setlock</span>.
</p>
<!-- ********************************************************************** -->
<h2 id="faq-integrating">Using getmail with other software</h2>
<p>
getmail user Frankye Fattarelli contributed to the following questions
about integrating getmail with SpamAssassin and ClamAV.
</p>
<h3 id="faq-integrating-spamassassin">How do I use SpamAssassin with getmail?</h3>
<p>
<a href="http://useast.spamassassin.org/index.html">SpamAssassin</a>
can be run in standalone mode or in a client/server configuration.
In both configurations, SpamAssassin accepts a wide variety of arguments;
please refer to SpamAssassin's manual pages or
<a href="http://useast.spamassassin.org/doc.html">online documentation</a>
for details.
</p>
<p>
To filter messages through SpamAssassin in a client/server configuration
(i.e. with the
<span class="file">spamd</span>
daemon), use a configuration like this:
</p>
<pre class="example">
[filter]
type = Filter_external
path = /usr/local/bin/spamc
arguments = ("-s 10000", )
</pre>
<p>
The value supplied to the
<span class="file">-s</span>
option is the maximum message size accepted (in bytes). The default
is 250k.
</p>
<p>
A similar configuration without the
<span class="file">spamd</span>
daemon would be:
</p>
<pre class="example">
[filter]
type = Filter_external
path = /usr/local/bin/spamassassin
arguments = ("--report", )
</pre>
<p>
The
<span class="file">--report</span>
option sends the message to the various spam-blocker databases and tags it
as spam in your bayesian database.
</p>
<p>
Note that if you are using Bayesian (learning) filtering, and you've put
your SpamAssassin filter
<em>after</em>
any getmail
<span class="file">Filter_classifier</span>,
you may have a problem with your learning filter learning getmail's
header fields. That is, the headers added by the other filters may get
learned, and affect your database. To prevent this, ensure that
SpamAssassin ignores these fields by adding the following to your
SpamAssassin configuration:
</p>
<pre class="example">
bayes_ignore_header X-getmail-filter-classifier
</pre>
<h3 id="faq-integrating-clamav">How do I use ClamAV with getmail?</h3>
<p>
You should also read <a href="http://article.gmane.org/gmane.mail.getmail.user/1486">this message</a>
in the getmail users' mailing list archives and the ClamAV documentation if
you want to use ClamAV with getmail.
</p>
<p>
<a href="http://www.clamav.net/">ClamAV</a>,
like SpamAssassin, can by used in standalone or client/server
configurations. In either case, you need to add the
<span class="file">StreamSaveToDisk</span>
option to your
<span class="file">clamav.conf</span>
file to enable scanning from stdin.
</p>
<p>
To use ClamAV without the
<span class="file">clamd</span>
daemon, use a filter configuration like this:
</p>
<pre class="example">
[filter]
type = Filter_classifier
path = /usr/local/bin/clamscan
arguments = ("--stdout", "--no-summary",
"--mbox", "--infected", "-")
exitcodes_drop = (1,)
</pre>
<p>
The above assumes you do
<em>not</em>
want the infected emails to be delivered. If you do want them delivered,
you would use a slightly different configuration:
</p>
<pre class="example">
[filter]
type = Filter_classifier
path = /usr/local/bin/clamscan
arguments = ("--stdout", "--no-summary",
"--mbox", "--infected", "-")
exitcodes_keep = (0,1)
</pre>
<p>
To use ClamAV with the
<span class="file">clamd</span>
daemon, use a filter configuration like this:
</p>
<pre class="example">
[filter]
type = Filter_classifier
path = /usr/local/bin/clamdscan
arguments = ("--stdout", "--disable-summary", "-")
exitcodes_drop = (1, )
</pre>
<p>
As with Clamscan (above), if you do want the infected messages delivered
instead of dropped, you should modify your configuration as follows:
</p>
<pre class="example">
[filter]
type = Filter_classifier
path = /usr/local/bin/clamdscan
arguments = ("--stdout", "--disable-summary", "-")
exitcodes_keep = (0,1)
</pre>
<p>
You may find it necessary to specify the paths of some decompression
utilities used by ClamAV with additional arguments like:
</p>
<pre class="example">
arguments = ( …,
"--unzip=/usr/local/bin/unzip",
"--unrar=/usr/local/bin/unrar",
"--unarj=/usr/local/bin/unarj",
"--lha=/usr/local/bin/lha",
"--jar=/usr/local/bin/unzip",
"--tar=/usr/bin/tar",
"--tgz=/usr/bin/tar"
</pre>
<p>
Note: if you want to use the daemonized (client/server) version of ClamAV,
ensure that your
<span class="file">clamav.conf</span>
file contains:
</p>
<pre class="example">
ScanMail
</pre>
<p>
The paths to the various decompression utilities must be specified in this
file as well.
</p>
<p>
See the following mailing list message from Frankye Fattarelli for
additional notes on using ClamAV with getmail:
<a href="https://marc.info/?l=getmail&m=109128345509273&w=2">https://marc.info/?l=getmail&m=109128345509273&w=2</a>
</p>
<h4 id="faq-integrating-clamav-prettier">Getting prettier output from ClamAV</h4>
<p>
Using getmail's Filter_classifier, the output of your filtering program
(in this case ClamAV) is placed into a
<span class="file">X-getmail-filter-classifier:</span>
header field in the message. This can make auditing the actions of
filters difficult if you use multiple filters and cannot tell which
filter added which line.
</p>
<p>
To correct this, you can use an additional filter to change the name of
the added filter header lines immediately after each filter is run.
For example,
<span class="file">reformail</span>,
from the
<a href="http://www.flounder.net/~mrsam/maildrop/">maildrop</a>
package (which is in turn part of the
<a href="http://www.courier-mta.org/">Courier MTA</a>
) can be used in this fashion to rename the added header fields
(say, to "X-mypersonalmailscan") with a filter configuration
like this:
</p>
<pre class="example">
type = Filter_external
path = /usr/local/bin/reformail
arguments = ("-R", "X-getmail-filter-classifier:",
"X-mypersonalmailscan:")
</pre>
<p>
Simply ensure ClamAV is invoked as the first filter, and this is invoked
as the second filter (or immediately after the ClamAV filter, if it is
the second, third, etc. filter).
</p>
<h3 id="faq-integrating-fprot">How do I use F-Prot with getmail?</h3>
<p>
getmail user Kai Raven reports that getmail and F-Prot work fine together
with the following getmailrc filter configuration:
</p>
<pre class="example">
[filter]
type = Filter_external
path = /usr/local/bin/f-prot-wrapper.sh
</pre>
<p>
The wrapper script
<span class="file">f-prot-wrapper.sh</span>
is a small shellscript by Ali Onur Cinar, and
<a href="http://www.zdo.com/articles/res/f-prot-wrapper.sh">can be downloaded from his website</a>.
</p>
<h3 id="faq-integrating-procmail">How do I use procmail with getmail?</h3>
<p>
Simply invoke
<span class="file">procmail</span>
as an
<a href="configuration.html#destination-mdaexternal">external MDA</a>.
<span class="file">procmail</span>
requires that one of the following be true:
</p>
<ul>
<li>
that the message begin with a Unix "From " line
(the mbox message delimiter)
</li>
<li>
that
<span class="file">procmail</span>
is invoked with the
<span class="file">-f</span>
option supplying the envelope sender, so that it may generate the
"From " line
</li>
</ul>
<p>
To have getmail generate and prepend the "From " line to the
start of the message, set the MDA_external
parameter
<span class="file">unixfrom</span>
to True:
</p>
<pre class="example">
[destination]
type = MDA_external
path = /path/to/procmail
unixfrom = True
</pre>
<p>
To supply the
<span class="file">-f</span>
option to procmail, do something like this:
</p>
<pre class="example">
[destination]
type = MDA_external
path = /path/to/procmail
arguments = ("-f", "%(sender)")
</pre>
<h3 id="faq-integrating-maildrop">How do I use maildrop with getmail?</h3>
<p>
Simply invoke maildrop as an
<a href="configuration.html#destination-mdaexternal">external MDA</a>.
maildrop requires that the message begin with a Unix "From " line
(the mbox message delimiter), so you'll need to either set the MDA_external
parameter unixfrom to True, or supply arguments that tell maildrop to
recreate this line. One of the following would be fine:
</p>
<pre class="example">
[destination]
type = MDA_external
path = /path/to/maildrop
arguments = ("-f", "%(sender)")
</pre>
<p>
Or:
</p>
<pre class="example">
[destination]
type = MDA_external
path = /path/to/maildrop
unixfrom = True
</pre>
<p>
If you want to specify a maildrop rc file as one of its arguments, that
would be something like:
</p>
<pre class="example">
[destination]
type = MDA_external
path = /path/to/maildrop
arguments = ("-f", "%(sender)", "~/.maildroprc")
</pre>
<h3 id="faq-integrating-tmda">How do I use TMDA with getmail?</h3>
<p>
Simply use the
<a href="configuration.html#conf-filters-tmda">Filter_TMDA</a>
module as a message filter:
</p>
<pre class="example">
[filter-X]
type = Filter_TMDA
</pre>
<p>
See the documentation for details on optional parameters to the
<a href="configuration.html#conf-filters-tmda">Filter_TMDA module</a>.
</p>
<h4 id="faq-integrating-gmail">How can I get Gmail labels with getmail?</h4>
<p>
As of getmail version 4.34.0, getmail retrieves the labels and other metadata
that Gmail makes available via an IMAP extension, and records that information
in the message headers
<span class="file">X-GMAIL-LABELS:</span>,
<span class="file">X-GMAIL-THRID:</span>,
and <span class="file">X-GMAIL-MSGID:</span>.
</p>
<!-- ********************************************************************** -->
<h2 id="faq-notabug">I think I found this bug in getmail …</h2>
<p>
I get frequent reports like the following, which aren't bugs in getmail.
Please read them before reporting them to me.
</p>
<h3 id="faq-notabug-gmail-bug">getmail doesn't download all my mail from Gmail …</h3>
<p>
There's a couple of different problems here. One is that Google's Gmail service violates
the POP3 protocol by removing messages from the POP3 view of the mailbox without the user
issuing a DELE command. They do this as soon as an RETR command is given, so if getmail
tries to download a message and it fails for any reason (delivery fails due to a full disk,
or the Gmail server fails to respond, or the network connection dies before the transfer is
complete, or the Gmail server fails to respond to the QUIT command, or …),
the next time getmail connects to that Gmail account, Gmail will have "helpfully"
deleted the message from the POP3 mailbox, even though getmail never issued a DELE command.
So Gmail silently destroys mail, from a POP3 perspective. There's nothing getmail can do
about this.
</p>
<p>
Note this feature of Gmail is <strong>not</strong> well-publicized. The only mention I
can find of it is here:
<a href="http://mail.google.com/support/bin/answer.py?answer=13291&topic=1555">http://mail.google.com/support/bin/answer.py?answer=13291&topic=1555</a>
</p>
<p>
The other issue here is that Google doesn't include mail from your trash or spam folders in
the POP3 view, so getmail can't see those messages either. That's generally less of an issue,
provided their spam filters never give false positive results (ha!).
</p>
<h3 id="faq-notabug-futurewarning">FutureWarning: %u/%o/%x/%X of negative int will return a signed string in Python 2.4 and up</h3>
<p>
Various people have reported this "bug" in getmail, where they
see the following warning when getmail is run:
</p>
<pre class="example">
/usr/lib/python2.3/optparse.py:668: FutureWarning: %u/%o/%x/%X of negative int will return a signed string in Python 2.4 and up
return ("<%s at 0x%x: %r>"
</pre>
<p>
This warning is a bug in Python 2.3.4's
<span class="file">optparse.py</span>
module, not in getmail. Feel free to report it to the Python team if the
most recent release of Python hasn't fixed it. I reported it in June, 2004.
</p>
<h3 id="faq-notabug-fsync">AttributeError: 'module' object has no attribute 'fsync'</h3>
<p>
Various people have reported this "bug" in getmail — it's
actually a bug in some versions of Python 2.3.X. It was fixed in Python
version 2.3.3. getmail 4 detects problematic versions of Python and refuses
to run, but you can still encounter this problem with getmail version 3
if you try to run it with a broken Python version.
</p>
<h3 id="faq-notabug-brokenpopserver">operation error (SimplePOP3Retriever: [...] does not uniquely identify messages [...] see documentation or use BrokenUIDLPOP3Retriever instead</h3>
<p>
The server you're trying to use does not properly uniquely identify messages
(getmail noticed when it saw the same "unique" identifier twice in
the same mailbox at the same time). getmail needs these identifiers to be
unique so that it can properly tell the difference between new and old
messages.
</p>
<p>
If you see this error message, and you've configured getmail to retrieve
and immediately delete all messages, just switch to using the
BrokenUIDLPOP3Retriever class (or its SSL variant) -- it'll work fine.
</p>
<p>
If you see this error message, and you're trying to leave messages on the
server after retrieval (permanently, or for a few days with
<span class="sample">delete_after</span>),
you have a few options to try to resolve it:
</p>
<ul>
<li>
If your provider also offers IMAP access to your mailbox, try one of
the IMAP retrievers instead.
</li>
<li>
Change your configuration so you're not leaving messages on the server,
and use BrokenUIDLPOP3Retriever instead.
</li>
<li>
Talk to your mail hosting provider, and see if they can fix their
POP3 software so that it doesn't have this problem any more.
</li>
</ul>
<h3 id="faq-notabug-osx-realloc">MemoryError on OS X</h3>
<p>
If you see errors like this while running getmail on Macintosh OS X:
</p>
<pre class="example">
python2.5(27172) malloc: *** vm_allocate(size=15699968) failed (error code=3)
python2.5(27172) malloc: *** error: can't allocate region
python2.5(27172) malloc: *** set a breakpoint in szone_error to debug
[...]
</pre>
<p>
... which then end with <span class="sample">MemoryError</span>,
please report the problem to Apple.
The
<a href="http://bugs.python.org/issue1092502">OS X implementation of realloc() is broken</a>,
and there's nothing getmail can do about it.
</p>
<h3 id="faq-notabug-memory">MemoryError when using IMAP</h3>
<p>
If you see errors like this while running getmail configured to retrieve
mail via IMAP or IMAP-over-SSL:
</p>
<pre class="example">
Python(24006) malloc: *** mmap(size=9875456) failed (error code=12)
[...]
</pre>
<p>
... which then end with <span class="sample">MemoryError</span>,
you've run into
<a href="http://bugs.python.org/issue1389051">a bug in Python's IMAP library</a>.
It's fixed in the most recent versions of Python 2.5 and 2.6. This bug can
cause getmail to grow to a huge size, vastly out of proportion to the size
of the message it's retrieving, at which point Python may fail or be killed
when the system runs out of memory.
</p>
<p>
Upgrade your Python installation to the newest Python 2.5 or 2.6 version to
fix the problem, or use POP3 instead of IMAP to work around it.
</p>
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