Thanks but I have that setting already.
The problem is the qmail environment puts in anonymous and the email gets bounced.
Like I said > I have fixed this with other php forms by adding something like
$MPForceSender = 'mail@address.com'; or
putenv('MAILUSER=mail@address.com');
in the file php file that processes the form.
If/when I find a solution I'll post back unless you can think of something else to try.