The reason the form data is in a string is this;
<FORM ACTION="mailto:[email protected]" METHOD="POST">
This code justs send all the value pairs as an email.
If you want the form details to arrive more legibly, you need to use a script of some kind.
Does your host provide CGI scripts, a CGI Bin or support PHP?
The easiest would be to use formmail...you can get this script free here click here
This script is used buy 1,000's of sites