I think what you are saying is that you need to have that email leave your server as a local account (i.e.
sk8guitar@university.edu), and they are probably leaving with something like
apache@your.box.com and getting bounced.
Is that right?
If so, you'd be better off to give the email a different "from" address that the server is allowed to relay. You just need to add it to the header info in your php email script.
Maybe something like:
$announce_to_email = "joe@yahoo.com";
$announce_from_email = "sk8guitar@university.edu";
$announce_from_name = "Your Name";
$mail_header = "MIME-Version: 1.0\r\n");
$mail_header .= "Content-type: text/plain; charset=iso-8859-1\r\n";
$mail_header .= "To: Someone <$announce_to_email>\n";
$mail_header .= "From: $announce_from_name <$announce_from_email>\n");
I think your university server just isn't relaying it, but if you can post more info about what's going on (error messages etc), I could be more help.
good luck!