Hi Mark,

I see your considerations about permissions, but I don't know are SELinux. What is this?

I stoped the python's services and I restarted the service with the command below:

root@serverlinux:/usr/local/mailman/bin# ./mailmanctl stop
Shutting down Mailman's master qrunner

root@serverlinux:/usr/local/mailman/bin# ps -fAww |grep python

root@serverlinux:/usr/local/mailman/bin# ./mailmanctl start
Starting Mailman's master qrunner.

After restarted the service, the following pid appear:

root@serverlinux:/usr/local/mailman/bin# ps -fAww |grep python
mailman  27184     1  0 12:54 ?        00:00:00 /usr/bin/python ./mailmanctl start
mailman  27185 27184  4 12:54 ?        00:00:00 /usr/bin/python /usr/local/mailman/bin/qrunner --runner=ArchRunner:0:1 -s
mailman  27186 27184 56 12:54 ?        00:00:02 /usr/bin/python /usr/local/mailman/bin/qrunner --runner=BounceRunner:0:1 -s
mailman  27187 27184  4 12:54 ?        00:00:00 /usr/bin/python /usr/local/mailman/bin/qrunner --runner=CommandRunner:0:1 -s
mailman  27188 27184  4 12:54 ?        00:00:00 /usr/bin/python /usr/local/mailman/bin/qrunner --runner=IncomingRunner:0:1 -s
mailman  27189 27184  4 12:54 ?        00:00:00 /usr/bin/python /usr/local/mailman/bin/qrunner --runner=NewsRunner:0:1 -s
mailman  27190 27184  4 12:54 ?        00:00:00 /usr/bin/python /usr/local/mailman/bin/qrunner --runner=OutgoingRunner:0:1 -s
mailman  27191 27184  5 12:54 ?        00:00:00 /usr/bin/python /usr/local/mailman/bin/qrunner --runner=VirginRunner:0:1 -s
mailman  27192 27184  5 12:54 ?        00:00:00 /usr/bin/python /usr/local/mailman/bin/qrunner --runner=RetryRunner:0:1 -s

The page continue with the error:

Bug in Mailman version 2.1.9

We're sorry, we hit a bug!
Please inform the webmaster for this site of this problem. Printing of traceback and other system information has been explicitly inhibited, but the webmaster can find this information in the Mailman error logs. 

Thanks for your help!!