What server for a mail server

[Ivan Voras]

Olivier Nicole wrote:
> Hi,
> 
> I have a project where I should set-up a mail server for approximately
> 12000 users, 4000 virtual domains, 15000 messages per day, 700 MB
> traffic per day.

Depending on how you interpret this information, its load is not that
high - this amounts to something like 10 messages per minute.

Any modern hardware (e.g. Xeon 51x0+, dual-core and better Opterons)
should handle this just fine.

> The machine should run Postfix, courrier-imap and a web mail (probably
> squirel), Apache 2, spamassassin, clamav, greylist

Scanning for spam and viruses will be the biggest bottlenecks. If you
want to go the safe route, move these tasks on an additional machine,
and use the main machine for everything else. Hardware is relatively
cheap nowadays, for example 2 Dells 2950 with a Xeon 5120 and with 4 GB
RAM each should do fine, or even one with double everything. Go for the
64-bit kernel since it will enable you to add more RAM.