[Mailman-Users] Mailman causing strange slowdown in SMTP

Mark Sapiro msapiro at value.net
Thu Aug 3 02:24:41 CEST 2006

Craig Pettersen wrote:

>This mailman installation serves only one list, an announcement only list,
>of about 35,000 members, with over 10,000 disabled due to bounces that send
>once every 2 weeks or so. It invariably sends
>several hundred to a thousand messages individually at the +/-15sec./message
>rate, then a big bulk mailing to most subscribers that's taking about 3000
>seconds for around 23,000, then a few score more of individual messages
>before it stops functioning.

What exactly is in Mailman's smtp and smtp-failure logs (the
'individual' messages are not the post).

>Using ps aux, one can see that all the
>qrunners are there and appear normal, but bin/mailmanctl must be used to
>stop and start things to get them going again.

When things are not going, what is the contents of the queues
(subdirectories of the qfiles/ directory)?

>  So my questions are...does anyone have any idea what mailman could be
>doing to interfere with smtp on its SMTPHOST and how to fix it? and does
>anyone have any idea why mailman stops working shortly after sending out the
>big list?

What are your various mm_cfg.py settings if any for the VERP settings

You might try


To see if that makes a difference.

If you restart both Mailman and qmail, does the first subsequent
Mailman SMTP session exhibit the 15 second delay?

Have you seen

Mark Sapiro <msapiro at value.net>       The highway is for gamblers,
San Francisco Bay Area, California    better use your sense - B. Dylan

More information about the Mailman-Users mailing list