Running a mail server is hard work. This is largely because it puts you on the front line of the battle with the internet’s biggest scourge: spam. My recommendation: don’t do it.
When I setup a new web site and domain, or when I am helping another organization setup their Email etcetera my preference is to sign-up for Google Apps and Gmail Email.
What is now Google Apps started with “Gmail For Your Domain” and now includes Gmail, Docs (documents), Groups, Sites and Chat. The standard edition is free for 50 accounts or less, above that it’s $50 per user per year.
The best part is Google handles all the spam filtering, gives users a number of Gigs of storage (7Gigs the last time I checked) and handles all the redundancy, backup etc, but it is worth noticing their no enterprise-esh recovery options.
There is even a Canadian connection in that Lakehead University in Thunder Bay was one of the first major domains to migrate everyone’s E-Mail. Many of the faculty objected to their Email being routed through the united states, but at least they were able to setup their iPhones with their work Email on Christmas day.
The most compelling reasons is that you get your mail via the best web interface going, as well as POP, IMAP, and SMTP servers that are all encrypted. Plus I’m a big fan of Google calendar system — I’m a big fan of calendar’ing systems in general.
Google Docs can be a bit of “lifestyle” change, but if you are interested working on documents, spreadsheets, and presentations online it’s a great service, espcially if you want to either work with others collaboratively in a work-flow or for sharing with an audience.