dovecot - Nov 2008 - dovecot pop3 performance, what size installation

Hello,

I was wondering if anyone could tell me their results and maybe help
me get an idea how big our mail system installation and usage is.

For dovecot pop3 and nfs backend, I am curious how many machines I
should expect to need.

Here are my stats for what I can tell. 5-7 connections per second
average, 8-12 connections per second peak. 30-50 constant connections
between 3 servers (8-20+) on each server. We are servicing about
14,000+ email accounts. These are just the pop3 login stats, a lot of
users use both or imap through our webmail.

My question I guess is whether this is on the small side, medium or
larger side mail setup, and should I be thinking that only 1 or 2
servers should be able to handle the load. Right now I am splitting it
between 3. Should a single quad core box be able to handle this? Not
sure if this is a simple question or not.

Im not including my dovecot -n just because this is more of a generic question.