My guess would be you don't have something configured properly with the [man]mail/man function.
At the very top of your script, add these two lines:
<?php
ini_set('display_errors', 1);
ini_set('error_level', E_ALL | E_STRICT);
[indent]Note: If you're still running php4, use: ini_set('error_level', E_ALL);[/indent]
Then try it again and see if any errors show up.