Most of the work for the "hacker alternative" is already done, in the form of [iRedmail].
[iRedMail]: http://www.iredmail.org/
[iRedMail]: http://www.iredmail.org/
It is by no means impossible that everything "just works" for you, but depending on your e-mail patterns, and what ISP you uses, and whether or not there's any spammers or spammer-look-alikes on the same netblocks as you, the level of hassle in ensuring your outbound e-mails actually gets delivered to your recipients inboxes rather than spam-filtered can be immense.