[Dovecot] partionning users among backends

[Emmanuel Dreyfus]

Hi

I face growing load on a mailserver, and I would like to spread the load
on multiple machines. I made a first attempt with dsync but got burnt with
issues with mbox, therefore now I am looking for another safer approach.

Partitionning users on multiple backends would address my load problem. 
I would have 50% of users on mail1.example.net and 50% on mail2.example.net,
but I need to correctly redirect users requests, as their mail user agents
only know about mail.example.net.

Is dovecot able to send request to the local machine or to proxy them 
to another one, depending on information it would have on user mailboxes
location? If it does, do we have documentation on this?

-- 
Emmanuel Dreyfus
manu at netbsd.org