FAQ   [plain text]

Mailman - The GNU Mailing List Management System
Copyright (C) 1998-2005 by the Free Software Foundation, Inc.
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA

Note: We're migrating the FAQ to an on-line interactive system called
      "FAQ Wizard".  To see the Mailman FAQ Wizard in action, go to


Q. How do you spell this program?

A. You spell it "Mailman", with a leading capital "M" and a lowercase
   second "m".  It is incorrect to spell it "MailMan" (i.e. you should
   not use StudlyCaps).

Q. I'm getting really terrible performance for outgoing messages.  It
   seems that if the MTA has trouble resolving DNS for any recipients,
   qrunner just gets really slow clearing the queue.  Any ideas?

A. What's likely happening is that your MTA is doing DNS resolution on
   recipients for messages delivered locally (i.e. from Mailman to
   your MTA via SMTPDirect.py).  This is a Bad Thing.  You need to
   turn off synchronous DNS resolution for messages originating from
   the local host.

   In Exim, the value to edit is receiver_verify_hosts.  See
   README.EXIM for details.  Other MTAs have (of course) different
   parameters and defaults that control this.  First check the README
   file for your MTA and then consult your MTA's own documentation.

Q. My list members are complaining about Mailman's List-* headers!
   What can I do about this?

A. These headers are described in RFC 2369 and are added by Mailman
   for the long-term benefit of end-users.  While discouraged, the
   list admin can disable these via the General Options page.  See
   also README.USERAGENT for more information.

Q. Can I put the user's address in the footer that Mailman adds to
   each message?

A. Yes, in Mailman 2.1.  The site admin needs to enable personalization by
   setting the following variable in the mm_cfg.py file:


   Once this is done, list admins can enable personalization for regular
   delivery members (digest deliveries can't be personalized currently).  A
   personalized list can include the user's address in the footer.

Q. My users hate HTML in their email and for security reasons, I want
   to strip out all MIME attachments.  How can I do this?

A. Mailman 2.1 has this feature built-in.  See the Content Filtering
   Options page in the admin interface.

Q. What if I get "document contains no data" from the web server, or
   mail isn't getting delivered, or I see "Premature end of script
   headers" or "Mailman CGI error!!!"

A. The most likely cause of this is that the GID that is compiled into
   the C wrappers does not match the GID that your Web server invokes
   CGI scripts with.  Note that a similar error could occur if your
   mail system invokes filter programs under a GID that does not match
   the one compiled into the C mail wrapper.

   To fix this you will need to re-configure Mailman using the
   --with-cgi-gid and --with-mail-gid options.  See the INSTALL file
   for details.

   These errors are logged to syslog and they do not show up in the
   Mailman log files.  Problems with the CGI wrapper do get reported
   in the web browser though (unless STEALTH_MODE is enabled), and
   include the expected GID, so that should help a lot.

   You may want to have syslog running and configured to log the
   mail.error log class somewhere; on Solaris systems, the line

       mail.debug                /var/log/syslog

   causes the messages to go to them in /var/log/syslog, for example.
   (The distributed syslog.conf forwards the message to the loghost,
   when present.  See the syslog man page for more details.)

   If your system is set like this, and you get a failure trying to
   visit the mailman/listinfo web page, and it's due to a UID or GID
   mismatch, then you should get an entry at the end of
   /var/log/syslog identifying the expected and received values.

   If you are not getting any log messages in syslog, or in Mailman's
   own log files, but messages are still not being delivered, then it
   is likely that qrunner is not running (qrunner is the process that
   handles all mail in the system).  In Mailman 2.0, qrunner was
   invoked from cron so make sure your crontab entries for the
   `mailman' user have been installed.  In Mailman 2.1, qrunner is
   started with the bin/mailmanctl script, which can be invoked
   manually, or merged with your OS's init scripts.

Q. What should I check periodically?

A. Many of the scripts have their standard error logged to
   $prefix/logs/error, and some of the modules write caught errors
   there, as well, so you should check there at least occasionally to
   look for bugs in the code and problems in your setup.

   You may want to periodically check the other log files in the logs/
   directory, perhaps occasionally rotating them with something like
   the Linux logrotate script.

Q. I can't access the public archives.  Why?

A. If you are using Apache, you must make sure that FollowSymLinks is
   enabled for the path to the public archives.  Note that the actual
   archives always reside in the private tree, and only when archives
   are public, is the symlink followed. See this archive message for
   more details:


Q. Still having problems?  Running QMail?

A. Make sure that you are using "preline" before calling the "mailman"

       |preline /home/mailman/mail/mailman post listname

   "preline" adds a Unix-style "From " header which the archiver requires.
   You can fix the archive mbox files by adding:

       From somebody Mon Oct  9 12:27:34 MDT 2000

   before every message and re-running the archive command
   "bin/arch listname".  The archives should now exist.  See README.QMAIL
   for more information.

Q. Still having problems?  Running on GNU/Linux?

A. See the README.LINUX file.

Q. I want to get rid of some messages in my archive.  How do I do

A. David Rocher posts the following recipe:

   * remove $prefix/archives/private/<listname>
   * edit $prefix/archives/private/<listname>.mbox/<listname>.mbox [optional]
   * run $prefix/bin/arch <listname>

Q. How secure are the authentication mechanisms used in Mailman's web

A. If your Mailman installation run on an SSL-enabled web server
   (i.e. you access the Mailman web pages with "https://..." URLs),
   you should be as safe as SSL itself is.

   However, most Mailman installation run under standard,
   encryption-unaware servers.  There's nothing wrong with that for
   most applications, but a sufficiently determined cracker *could*
   get unauthorized access by:

   * Packet sniffing: The password used to do the initial
     authentication for any non-public Mailman page is sent as clear
     text over the net.  If you consider this to be a big problem, you
     really should use an SSL-enabled server.

   * Stealing a valid cookie: After successful password
     authentication, Mailman sends a "cookie" back to the user's
     browser.  This cookie will be used for "automatic" authentication
     when browsing further within the list's protected pages.  Mailman
     employs "session cookies" which are set until you quit your
     browser or explicitly log out.

     Gaining access to the user's cookie (e.g. by being able to read
     the user's browser cookie database, or by means of packet
     sniffing, or maybe even by some broken browser offering all it's
     cookies to any and all sites the user accesses), and at the same
     time being able to fulfill the other criteria for using the
     cookie could result in unauthorized access.

     Note that this problem is more easily exploited when users browse
     the web via proxies -- in that case, the cookie would be valid
     for any connections made through that proxy, and not just for
     connections made from the particular machine the user happens to
     be accessing the proxy from.

   * Getting access to the user's terminal: This is really just
     another kind of cookie stealing.  The short cookie expiration
     time is supposed to help defeat this problem.  It can be
     considered the price to pay for the convenience of not having to
     type the password in every time.

Q. I want to backup my lists.  What do I need to save?

A. See this FAQ wizard entry:

Q. How do I rename a list?

A. Renaming a list is currently a bit of a pain to do completely
   correctly, especially if you want to make sure that the old list
   contacts are automatically forwarded to the new list.  This ought
   to be easier. :(

   The biggest problem you have is how to stop mail and web traffic to
   your list during the transition, and what to do about any mail
   undelivered to the old list after the move.  I don't think there
   are any foolproof steps, but here's how you can reduce the risk:

   - Temporarily disable qrunner.  To do this, you need to edit the
     user `mailman's crontab entry.  Execute the following command,
     commenting out the qrunner line when you're dropped into your
     editor.  Then save the file and quit the editor.

     % crontab -u mailman -e

   - Turn off your mail server.  This is mostly harmless since remote
     MTAs will just keep retrying until you turn it back on, and it's
     not going to be off for very long.

   - Next turn off your web server if possible.  This of course means
     your entire site will be off-line while you make the switch and
     this may not be acceptable to you.  The next best suggestion is
     to set up your permanent redirects now for the list you're
     moving.  This means that anybody looking for the list under its
     old name will be redirected to the new name, but they'll get
     errors until you've completed the move.

     Let's say the old name is "oldname" and the new name is
     "newname".  Here are some Apache directives that will do the
     trick, though YMMV:

     RedirectMatch permanent /mailman/(.*)/oldname(.*) http://www.dom.ain/mailman/$1/newname$2
     RedirectMatch permanent /pipermail/oldname(.*)    http://www.dom.ain/pipermail/newname$1

     Add these to your httpd.conf file and restart Apache.

   - Now cd to the directory where you've installed Mailman.  Let's
     say it's /usr/local/mailman:

     % cd /usr/local/mailman

     and cd to the `lists' subdirectory:

     % cd lists

     You should now see the directory `oldname'.  Move this to

     % mv oldname newname

   - Now cd to the private archives directory:

     % cd ../archives/private

     You will need to move the oldname's .mbox directory, and the
     .mbox file within that directory.  Don't worry about the public
     archives; the next few steps will take care of them without
     requiring you to fiddle around in the file system:

     % mv oldname.mbox newname.mbox
     % mv newname.mbox/oldname.mbox newname.mbox/newname.mbox

   - You now need to run the `bin/move_list' script to update some of
     the internal archiver paths.  IMPORTANT: Skip this step if you
     are using Mailman 2.1!

     % cd ../..
     % bin/move_list newname

   - You should now regenerate the public archives:

     % bin/arch newname

   - You'll likely need to change some of your list's configuration
     options, especially if you want to accept postings addressed to
     the old list on the new list.  Visit the admin interface for your
     new list:

     o Go to the General options

     o Change the "real_name" option to reflect the new list's name,
       e.g. "Newname"

     o Change the subject prefix to reflect the new list's name,
       e.g. "[Newname] " (yes, that's a trailing space character).

     o Optionally, update other configuration fields like info,
       description, or welcome_msg.  YMMV.

     o Save your changes

     o Go to the Privacy options

     o Add the old list's address to acceptable_aliases.
       E.g. "oldname@dom.ain".  This way, (after the /etc/aliases
       changes described below) messages posted to the old list will
       not be held by the new list for "implicit destination"

     o Save your changes

   - Now you want to update your /etc/aliases file to include the
     aliases for the new list, and forwards for the old list to the
     new list.  Note that these instructions are for Sendmail style
     alias files, adjust to the specifics of how your MTA is set up.

     o Find the lines defining the aliases for your old list's name

     o Copy and paste them just below the originals.

     o Change all the references of "oldname" to "newname" in the
       pasted stanza.

     o Now change the targets of the original aliases to forward to
       the new aliases.  When you're done, you will end up with
       /etc/aliases entries like the following (YMMV):

       XXX This needs updating for MM2.1!

       # Forward the oldname list to the newname list
       oldname:         newname@dom.ain
       oldname-request: newname-request@dom.ain
       oldname-admin:   newname-admin@dom.ain
       oldname-owner:   newname-owner@dom.ain

       newname:         "|/usr/local/mailman/mail/mailman post newname"
       newname-admin:   "|/usr/local/mailman/mail/mailman mailowner newname"
       newname-request: "|/usr/local/mailman/mail/mailman mailcmd newname"
       newname-owner:   newname-admin

     o Run newaliases

   - Before you restart everything, you want to make one last check.
     You're looking for files in the qfiles/ directory that may have
     been addressed to the old list but weren't delivered before you
     renamed the list.  Do something like the following:

     % cd /usr/local/mailman/qfiles
     % grep oldname *.msg

     If you get no hits, skip to the next step, you've got nothing to
     worry about.

     If you did get hits, then things get complicated.  I warn you
     that the rest of this step is untested. :(

     For each of the .msg files that were destined for the old list,
     you need to change the corresponding .db file.  Unfortunately
     there's no easy way to do this.  Anyway...

     Save the following Python code in a file called 'hackdb.py':

     import sys
     import marshal
     fp = open(sys.argv[1])
     d = marshal.load(fp)
     d['listname'] = sys.argv[2]
     fp = open(sys.argv[1], 'w')
     marshal.dump(d, fp)

     And then for each file that matched your grep above, do the

     % python hackdb.py reallylonghexfilenamematch1.db newname

   - It's now safe to turn your MTA back on.

   - Turn your qrunner back on by running

     % crontab -u mailman -e

     again and this time uncommenting the qrunner line.  Save the file
     and quit your editor.

   - Rejoice, you're done.  Send $100,000 in shiny new pennies to the
     Mailman cabal as your downpayment toward making this easier for
     the next list you have to rename. :)

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