[TriLUG] sendmail vs. postfix - was Re: stupid sendmail question?

[Jon Carnes]

On Thu, 2004-06-17 at 13:19, Michael Alan Dorman wrote:
> "Ben Pitzer" <uncleben at mindspring.com> writes:
> 
> > The fact is that none of us, to my knowledge, have ever tried to
> > scale Postfix to extreme levels, but I'd be interested to hear from
> > some party who has tried to do so.  Perhaps we could ask Weitse if
> > he knows of anyone who has tried, and what level of success they
> > have experienced.
> 
> What are extreme levels?
> 
> I run an anti-spam service, and we easily handle 2 messages/sec on
> $1700 systems that are doing the mail receiving, spam filtering, virus
> scanning, forwarding as well as storage and retrieval (through a web
> interface) of sidelined mail.
> 
> I have, in test situations, pumped at least 8 messages/sec through
> less powerful systems.
> 
> Are those considered extreme?
> 
> Mike

Not to brag or anything, but I have a site I setup two years ago using
Sendmail, SpamAssassin, McAfee Anti-virus, and MailScanner which
averages about 20 messages/second (the HW costs were around $2400 two
years ago). 

Sendmail works like a champ on that system!

At the time I set that system up I did some stress testing using
Sendmail and Postfix.  I don't remember the exact numbers, but at that
time Sendmail considerably out performed Postfix at that level of
traffic (using the same hardware/applications setup).

I was fairly shocked at the time that Postfix faired so poorly; but
someone on the Mailscanner list pointed out that running a strace on
sendmail and one on Postfix would showed that Postfix performed a
massive number of processing steps to process a single message (as
compared to Sendmail).  Looking at Postfix's architecture that makes
sense.

As someone else already pointed out - if you want to use Postfix - you
can simply throw more hardware into the mix and get whatever level of
performance you want. I prefer Sendmail as it gives me the best
performance (Note: I do tweak Sendmail so that it acts like an optimized
MTA - you can see my website for details on that).

Jon Carnes