Source: http://arstechnica.com/information-techn...

E-mail is hard. If you want an easier sysadmin project, go set up a Web server. E-mail is a lot more complex, with many more moving parts. On the other hand, your correspondence with others is one of the most personal aspects of your online life—in a medium ultimately made of text, your words are you. It's worth learning how to claw your online life back from those who would data mine and monetize it.

There are pitfalls and caveats—the biggest of which is that if you run your own e-mail server, you will be the sysadmin. The upside of this is that no bored or tired customer service rep about to go off-shift is going to fall for a social engineering attack and reset your e-mail password. The downside is that you are responsible for the care and feeding of your system. This is not an impossible task—it's not even really difficult—but it is non-trivial and never-ending. Applying critical updates is your responsibility. When do critical updates come out? That's your responsibility to keep track of, too.

Worst of all, if you screw up and your server is compromised or used as spam relay, your domain will almost certainly wind up on blacklists. Your ability to send and receive e-mail will be diminished or perhaps even eliminated altogether. And totally scrubbing yourself from the multitude of e-mail blacklists is about as difficult as trying to get off of the TSA's No Fly list.

You have been warned.