[Mailman-Users] Sendmail Performance with mailman

[Graham TerMarsch]

On May 3, 2002 12:18 pm, Bueschel, Eric W RWBAHC DIN-PACS wrote:
> As of today, I am no longer getting failures in the smtp-error logs,
> however it seems that incoming messages are parsed to mailman, then
> queued for 10 to 40 minutes where they just wait.  No errors, no
> timeouts, they just wait. Here is a sample from the sendmail output:
[.....snip.....]

From having used Mailman+Sendmail together for quite some time, I'd wager a 
guess that the behaviour that you're seeing is related to the way that 
you've got Sendmail configured.

If you're using "-ODeliveryMode=defer", then what you're telling Sendmail 
is to just queue the message up for later delivery and _NOT_ to attempt to 
send it right now.  When Sendmail comes along later and does a queue run, 
it'll find the msg, and whisk it off on its way.  When you're using the 
box as a relay or for local mail, you're not connecting to it on port 
1313, so its not using the "deferred" delivery mode.

Feel free to reply off-list if you'd like to go into greater detail on 
this.  I know that Chuq here has used Sendmail for some time now, and I 
used it for a list I work with up to ~250k subscribers.  At that point we 
switched the machine over to Postfix as I couldn't get Sendmail to send 
the msgs out fast enough, even with all the tunes and tweaks that we had 
in place.  Not to say that Sendmail can't handle that kind of load, it 
just couldn't handle it on the hardware that we had available at that 
time; on the same hardware Postfix gave us better performance for our 
lists.

Don't take me wrong, though, I do like Sendmail, and have used it for many 
years quite successfully; for _really_large_ lists, though, I found it 
easier to tune things with Postfix.  If you'd like extra assistance in 
getting your Sendmail install tuned properly for your list, do feel free 
to drop me a note off-list and I'd be happy to help out.

-- 
Graham TerMarsch
Howling Frog Internet Development, Inc.   http://www.howlingfrog.com