[Mailman-Users] List performance and server size

Mike Avery mavery at mail.otherwhen.com
Wed Jul 13 20:05:20 CEST 2005

Dave Beckstrom wrote:

>I have a client who needs to send out about 50,000 emails once a month via a
>one-way list.
The unmentioned things here are, how fast to the emails have to leave 
the server and reach the users and how large are the emails?

If the emails are relatively small, even a DSL line could get the emails 
out in a reasonable time frame.  If they are large, and you have to get 
them out quickly, you could have some bandwidth issues.

While 50,000 emails sounds like a lot, the fact you're only sending one 
email a month means you are probably wasting money throwing a mega 
server at it.

>I'm considering installing Mailman on a Dell server with a 2.8 ghz Xeon
>processor, 1 GB ram and one 160 GB SATA IDE Hard drive.
>The OS would be FreeBSD.
At this time, I'm using a 733 pentium III with a 40gig ATA drive and 384 
megs of ram.  Its running FreeBSD 4.8, and it is running IPFW, NATD, 
DHCPD, NTPD, Squid, Apache,  Postfix, and Mailman.  It's hosting about 
12 web sites (some of which are pretty active) and 15 mailing lists 
ranging from small to large (about 1,000), with activity all over the 
place.  Most of the lists are interactive, not announcement lists.  No 
performance issues.  15 mb of ram is still free, and only 147K of swap 
space has ever been used.  We're using a slow 256kbps DSL line.

The big hit is when on the first of the month all our subscribers get 
their Mailman reminders.  The queue is clear before I get into the 
office at 8:00 AM.

Mailman and Postfix installed pretty cleanly from the ports collection.

I think in your shoes, I'd do a test run on a more modest server and see 
what the performance is like, and then look at where the actual 
bottlenecks are.  FreeBSD is pretty friendly about being moved from one 
machine to another... just put your hard drive into a faster machine, 
make sure they have the same NIC and you can probably be running without 
having to change anything.

I honestly suspect that your real performance hit will be list aging.  
 From what I've read and seen, most lists, if they aren't maintained, 
have about 10% of their addresses go stale every month.  That means 
you'll get about 5,000 bounces the first month.  And handling bounces is 
a waste of bandwidth and system resources.  I'd make sure you turn on 
VERP and prune aggressively.  With only one mail going out a month, you 
have to use fairly aggressive pruning settings or the bad addresses will 
never age out.

Look at the FAQs to see how to make Mailman work with your MTA and 
VERP.  It took me about 1/2 a day with Postfix.  (Because the system 
works so well, I don't have to tweak it often, so, despite using FreeBSD 
for years and years and the Mailman/Postfix combination for years, I'm 
still a perpetual newbie in FreeBSD, Mailman, and Postfix.)


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