Advice on webmail server

[Metrion]

Hi all,

I'm hoping someone can give me some tips on setup for a server I'm
making. It's going to be a webmail server for a client, with probably
no more then 700-800 total accounts, with maybe up to 250 concurrent
users. Will be some HTML mail (bleh!) and flash/animated gif/etc also.
I thought of Squirrelmail as the likely candidate. Mostly internal
connections, with external via SSL available. Bandwidth isn't an
issue.

The server is a HP ProLiant DL380, twin 2.8GHz Xeon, 2G ram. 2x36.4G
10k Ultra320 and 4x72.8G 10k Ultra320.

I have the 36.4G drives mirrored, for OS and config stuff, and was
going to make the 4x72.8G a raid5 and that be the mail spool
partition. Is that sound like a good idea?

I've not used FreeBSD for anything like this before and frankly am not
sure what changes from default I should use, if any. Should I stick
with 4.10, or is 5.2.1 OK? Any sysctl changes? Default kernel OK?


Thanks for any tips! 

-- 
Met