[Dovecot] Improving lmtp performance

[Stan Hoeppner]

Joseba Torre put forth on 2/2/2011 4:14 AM:

> yesterday I migrated and old version with sendmail + courier to a virtual 
> machine (vmware) with postfix and dovecot 2.0.9.
> 
> Everything worked fine, but with a more or less default setup for both dovecot 
> and postfix, lmtp performance was pretty bad: a message was written to an 
> inbox every 2 or 3 seconds. With that rate and a 5000+ and growing mail queue 
> mail delivery was really slow.

<snip>

> Now mail delivery is really fast, and my mail queue was delivered in a very 
> sort time. Is this the right solution, or there's a better setup to improve 
> mail delivery performance?

You've posted no log data.  It's pretty difficult to diagnose problems without
log entries.  Do you just want us to guess?

> Also, if this is a common problem, may be something should appear in 
> http://wiki2.dovecot.org/LMTP

That's a bit premature.  The problem could just as likely be a Postfix
configuration error.  Get us some logs from both Postfix and Dovecot for the
previous configuration with the slow performance.

Are both Postfix and Dovecot running in the same VM guest OS instance or two
separate VM guests?  Are you running elaborate Sieve scripts?  Are you running
AV/AS in Dovecot?  Anything relatively CPU heavy in Dovecot on a per message basis?

-- 
Stan