[Mailman-Users] Re: Troubleshooting: no mail goes out to lists - common things to check

peter schoch pschoch at sussex.cc.nj.us
Sat Nov 9 23:31:22 CET 2002

Jon,  this was a great posting!  I think it would probably be good to add to the FAQ page on the mailman site.  I'd add that you might need to tweak sendmail's settings to allow some domains to forward to get this to work.

All of your 'checks' were OK for me, and yet the lists were still not working.  Then, on Friday, the lists just started sending.

One of the subscribers had forgotten to remove their auto-reply "Out of Office" message.  It replied multiple times to the subscription notices, and then the lists started and the auto-reply caused a huge number of posts!  But now the lists have kept working.

I have no errors, etc. in the logs.  I have no idea of why it just started. I didn't change anything, modify anything...  I'd feel better if I knew why, but...

Tahnks for all of the help.
Peter Schoch
              Here are some common things to check when no mail is going out from your 

              I'm going to assume Sendmail as the MTA (its still the most commonly 
              found - though postfix is gaining ground): 

              0) Check_perms. In all cases you should start by checking the 
              permissions on the files that were setup: 


              1) Cron. Make sure that the cron daemon is running 

              ps -aux |grep cron |grep -v grep 

              This will print out the process information about the cron 
              daemon. If it returns a blank line, then cron is NOT running. 

              2) Aliases. To create a mailman list you ran "newlist" and it 
              printed out four lines that you needed to copy to the 
              /etc/aliases file (or wherever your MTA goes to find its 
              aliases). Check that the aliases are in /etc/aliases: 

              grep wrapper /etc/aliases 

              Even if the aliases are there, you may still need to reset 
              the aliases hash table so that it includes this new alias 


              Here is a typical alias listing for a group called "sys": 

              ## system mailing list 
              sys: "|/home/mailman/mail/wrapper post sys" 
              sys-admin: "|/home/mailman/mail/wrapper mailowner sys" 
              sys-request: "|/home/mailman/mail/wrapper mailcmd sys" 
              sys-owner: sys-admin 

              3) Smrsh. Check to see if your MTA uses smrsh. Red Hat as well 
              as a few other distributions automatically setup Sendmail to 
              use smrsh. Smrsh stops Sendmail from running a script or 
              other program that is included in an alias. Mailman uses a 
              program called "wrapper" to run all of its aliases (see the 
              alias examples above): 

              grep "smrsh" sendmal.cf 

              If this comes up blank then Sendmail does not use smrsh; 
              if not, then your server is probably running smrsh and you 
              need to make sure that smrsh is setup to allow Mailman's 
              wrapper program to run. Locate the smrsh directory and do 
              an ls -l of that directory. On Red Hat: 

              ls -l /etc/smrsh 

              and the output should be similar to: 

              wrapper -> /home/mailman/mail/wrapper 

              4) Interface. Some distributions in a noble "attempt" to limit 
              the number of open relays on the internet, default Sendmail 
              so that it listens to a limited number of interfaces. The 
              default interface that Mailman list's use is localhost 
              ( - this is configurable in Mailman's mm_cfg.py 
              file. To check Sendmail's configuration file: 

              grep "Port" sendmail.cf 

              This will list out the DeamonPortOption and indicate the 
              interfaces it listens on ( would mean all interfaces). 

              You can also check out which interfaces your MTA is listening 
              on by using: 

              netstat -na |grep ":25 " 

              5) Qrunner. If you are running Mailman 3.0x then qrunner is 
              run every minute via a cron job (that is why cron *must* be 
              running for Mailman to work). Try running the program by 
              hand. The exact syntax can be found in Mailman's cron jobs: 

              su mailman 
              crontab -l 

              Here is an example of running qrunner by hand: 

              su mailman 
              /usr/bin/python -S /home/mailman/cron/qrunner 

              If this generates any errors then send those to the list 
              for diagnosis - or look at the last few lines of errors and 
              search the list for key words from the error messages. 

              6) Locks. A errant lock file can stop a list from processing as 
              Mailman waits for the lock to be removed. Since your list is 
              not sending, we shall assume that no lock files should be on 
              the list and that it is safe to delete any we find. 

              ls -l ~mailman/locks 

              The output will be something like: 


              This indicates that process # 22845 created the lock. To look 
              at this process and see what it is (if it still exists): 

              ps aux |grep 22845 |grep -v grep 

              7) Logs. If you don't have any of the common problems above, 
              then you should look for errors in your log files. 

              First look for errors in your MTA log files. On Red Hat that 
              would be in /var/log/maillog. 

              Look in the log starting at the time you sent a test message. 
              You should see your initial message come in and be passed 
              onto to your Mailman list, afterwards you may see warnings 
              or errors caused by Mailman trying to send out mail to the 
              members of the list. 

              Next look in Mailman's logs. The files are in ~mailman/logs/. 
              There are several logs to look in for problems: 

              Note: if you look in the qrunner log you will see several 
              warnings about "Could not acquire qrunner lock", these are 
              actually normal and are NOT a problem. 

              Every line in the log files is dated so you should be able to 
              isolate the place in the log files to start looking, based on 
              when your problem started. 

              8) Qfiles. You may have a malformed email (or one that is simply 
              too big) clogging up the flow of mail to your lists. Mail 
              that is queued up by Mailman is stored in the directory: 

              Move any files out of the directory and into a temporary 
              directory, then send a new test message to your list. If that 
              works, then you can move some of the old queued up files back 
              and let those process. If it stops working again then you 
              have a bad message in that batch - delete them or copy them to 
              a different temporary directory. 


              Please feel free to critic and expand on this. I'm hoping that it 
              proves useful as a starting point for folks having mail-flow problems. 

              -- Jon Carnes 

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