[Mailman-Users] sending email step

Roberto Ullfig rullfig at uchicago.edu
Mon Mar 6 19:20:25 CET 2000

Paul Tomblin wrote:
> Quoting Roberto Ullfig (rullfig at uchicago.edu):
> >
> > How does mailman actually send the messages to the users on a
> > list? Does it call sendmail in parallel or serial? Is there a
> > pause between each message getting sent or does it try to use
> > all of a system's resources? We think that some large lists are
> > bringing our system down to its knees.
> You can configure how many sendmail processes it spawns per message, and it
> makes those connections in parallel.  However, each sendmail process will
> process its list serially.  If you find large lists are bogging your system
> down in terms of flooding the network, you might want to make it fewer
> connections so that it only works on one destination per message at a time.
> However, if it's a CPU thing, you might want to look into raising or lowering
> that number, OR you might want to look into a different MTA.  I switched to
> postfix and it's tons faster than sendmail.  I've heard good things about exim
> and qmail - although the author of qmail is a prick and you don't want to deal
> with him if you can avoid it.


I assume you're talking about the mailman num_spawns variable
then? (default is 5) - should we lower this for very large lists
then? Can this be configured for all lists? Is there a global
setting somewhere?

Our problem was with running out of memory, does postfix use
less memory than sendmail? Postfix would not make anything
noticeably faster for us; phquery is our bottleneck.

Thanks in advance!

Roberto Ullfig : rullfig at uchicago.edu
Systems Administrator
Networking Services and Information Technologies
University of Chicago

More information about the Mailman-Users mailing list