[Dovecot] Need suggestion regarding index file and Quota settings.

[Ed W]

Off the wall, but have you also considered using Dovecot (or other 
software, eg nginx) proxy options?

I only have a small setup, but I have seen others use the idea that all 
backend servers are also frontend servers, but the proxy option then 
forwards the connection to the correct other machine (with only a few 
servers the probability they hit the correct server first time is also 
respectable).

You can also stick a single proxy only machine in front of 
everythingthing else to point connections to the correct backend 
straight off.  Dovecot is apparently respectable as a high performance 
frontend proxy - some other people like nginx (no personal experience)

I believe you will find instructions on using indexes on NFS on either 
the wiki or a couple of previous answers from Timo here.  I think 
basically that v1.1 is best for indexes on NFS?

Good luck

Ed W