I have a large mailing list with Mailman (+4000 members) on my Cpane server (Linux CentOS 4, WHM 11.15.0 cPanel 11.18.1) . I sent out a message yesterday, most of the emails were delivered successfully. Only a few emails were still hanging in the queue, which is normal. Today, I restarted Cpanel, and suddenly this old email was resent again in mass to everyone. When Cpanel was restarted again later today by my system admin, Mailman started to send the same message for the 3rd time, so I had to shut down exim server a moment ago to avoid my server being blacklisted by Yahoo/Hotmail/Gmail. Also since early today, I observed that I couldn't send new emails to any mailing lists. I can see from the exim mail server's log file that exim successfully received the new message, but it couldn't activate the mailman to distribute it. From the above two symptoms, I suspect that something is wrong with mailman. How can I solve it? Thanks in advance!