[Dovecot] Improving lmtp performance

[Joseba Torre]

Hi,

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.

After searching both the wiki and this list I didn't find anything related to 
this. I tried a couple of things, and finally added

process_min_avail = 10

to service lmtp entry in 10-master.conf and

local_destination_concurrency_limit = 10

in postfix's main.cf

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?

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

Thanks.
-- 
Joseba Torre. Vicegerencia de TICs, área de Explotación