I need to build a box for a huge email system.
I would like to get your opinions in this matter.
From your experience: how many users with 10-20 MB quota for each can you put on one box? What is the highest record of users you had in one box.
I need to build a box for 5000 users.
Which OS will do the best? linux/bsd ?
Which email software is the best to handle it?
Which hardware configuration would you recommend and why?
What is most important for such system? RAM? CPU? DISK?
Well I don't expect answers of 8 CPU's 50 gig of ram etc. but the best value without making my customer run away when he will hear the quote
Please ass as much tips as you can - because I am sure I will need it

biz -

Ev1.net now hosts around three quarters of a million 10 meg mailboxes. My architecture is now completely different, but I reached a limit of about 20k active, full featured (imap/webmail) mailboxes on a single CPU Windows system, not much RAM and a SCSI HDD array.

Without question the bottleneck for me was the HDD IO. Generally the nature of email is lots of 1-4 KB messages stacked up in mailbox files. Then the user checks his mail and the mail clears - over and over. This quickly leads to disk fragmentation which only makes HDD IO worse.

I would think 5,000 mailboxes should be not much problem with any 'nicely appointed' server.

Good luck.

Randy Williams, CTO
Ev1.net, Rackshack.net

thanks for your input.
i wish i will get more tips/ideas/opinons about how to build such email system. especially which Mail servewr will do best.

Originally posted by Techiesurfer
Ev1.net now hosts around three quarters of a million 10 meg mailboxes. My architecture is now completely different

You willing to share the a high level overview for the curious?

Try qmail -> http://cr.yp.to/qmail.html
It can handle a ridiculous amount of mail on even a small box. I heard redhat.com runs qmail on a 486 for their domain.

OS=Red Hat Linux
Email software=Qmail
Hardware=Dual Processor and SCSI Drives

:D