A Cyrus/murder of that size is possible?

[Sergio Devojno Bruder]

I'm planning a large mail system with the postfix / lmtp / cyrus in
murder / mysql (users table) configuration.

The system will be used in ISP-pattern: huge number of users
(500k), high traffic of emails arriving by lmtp (15 emails per
second), but low imap/pop3 demand (peaks of 2000 simultaneous
users, more pop3 than imap).

All configurations that I saw with cyrus was talking about
imap/pop3 use, I never saw any published benchmarks|comparitions of
cyrus with MTAs doing local delivery by lmtp|smtp.

I have some questions:

- Using storage with fiber in my ia32 backend servers, how much
  users can I squeeze in one box? (ie, how much emails/s in
  lmtp can I get AND how much concurrent pop3|imap users can one
  box cope with?) (P4's 2G RAM with fiber to an EMC);

- I'm toying with the idea of create a mutant postfix
  mpudate-enabled that will deliver the email directly to the right
  backend, using the murders servers only to pop3 and imap.
  feasible or I'm getting nuts?

--
Sergio Devojno Bruder   <bruder at haxent.com.br>
Haxent Consultoria    http://www.haxent.com.br
55 41 9127-6620