Well, your first option is to simply make your form tag look like:
Code:
<form action='mailto:me@mydomain.com' method='post' enctype='text/plain'>
That, though, will require the user to have an email client configured on their computer, and will, in most cases, require them to press the "Send/Receive" button in their email client.
Your next option is to go with something like
Phorm or whichever PHP form processor Leprakawn likes to recommend (I can't remember off the top of my head which one that is).