If you want to do e-mail, I would suggest Microsoft Exchange Server. Of course that's going to cost a bit, but that's what I would use.

Exchange 2000/2003 are setup for use with SMTP email accounts by default, so you would contact your ISP and ask them to update the MX records for your domain name to send mail straight to your server.
Alternatively of course you could use POP3 to check for mail yourself...