the error is probably a blank space or blank line after the closing php tag of the error reporting code.
see the following thread for details:
showthread.php?t=19285
you did not mention who the host was?
Most hosts require that the From Address be a valid email address for the domain or they wont relay the message.
did you add the session dump code to the success page?
The session dump will help us determine if the email is getting to the SMTP server or not.