You may be interested to check out SmarterMail as an alternate Windows Mail Server. The free edition runs in Enterprise paid edition mode with 10 mailboxes with no expiration timeline. You could manage the mail server via an admin web interface without the need to login to the server via RDP and it also support the SSL/TLS. Take a look at http://www.tweakservers.com/products/smartertools/smartermail/
Thanks for the suggestion but the download would not start. I'll keep trying but in the mean time, I'm still exploring other options.