This is by far one of the best mail servers I have come across for the price – free. Gotta love open-source. I set it up over the weekend as my new mail server, and I can’t believe how efficient this thing is over against my old mailserver, ArgoSoft (which you have to pay for by the way). So I’ve dumped ArgoSoft for this. So far, the anti-spam tools in it work a lot better as well. Amazing stuff.
hMailServer – Best Open-Source Mail Server for Windows