What is the best mail server software, compatible with G5 and OS X 10.5.8?

Question

Hello.
I want to install/set up a mailserver on Mac OS X 10.5.8.
It will host approximately 35users, should have pop, imap, spam protection, webmail/admin interface, routing feature, all the usual stuff, I'm doing this because we often have to recieve very large files and having a mailserver on local network makes working with them so much faster. What would you recommend?
Thanks in advance.

Answer 1

There isn't enough data in your post to create an informed answer.
For one, are you talking Mac OS X client, or Server?
Mac OS X Server already includes all the various mail server components you talk about, and it's based on Postfix, one of the most popular open source mail servers around.
Secondly, having your own mail server will only be 'so much faster' for local users sending/receiving local mail (i.e. from users on the same network). Every other email has to go out (or come in) over your office internet connection and having your own mail server doesn't change that one bit.
At that point, if you're only talking local users, it sounds like what you want is a file server, not a mail server. Mail is not designed for large file transfers.
Third, even if you don't want Mac OS X Server's solution, and you can deal with the bandwidth, you haven't mentioned cost - what's your budget here. You won't find a free/open source solution that's more complete and easier to use than Apple's bundle, so now you're into the commerical offerings. All of them charge, typically per user and some of them (as already mentioned) are mothballing their PPC support, meaning any invenstment in their option might be short-lived.
So I think you need to better state your goals and ideals before you can find the 'best' solution (if any of them are really 'better' than any other).