or download this
open (MAIL, "|$mailprog -t") or &dienice("Can't access $mailprog!\n");
print MAIL "To: $FORM{'my_email'}\n";
print MAIL "Reply-to: $FORM{'email'}\n";
...
print MAIL "Subject: Transaction Notification\n\n";
print MAIL "$emailbody\n";
close(MAIL);