I don't see why it has to be called print (this was mentioned as a specific error reporting problem, I believe)...

sub writeError {
  print STDERR @_;
  print FILE @_;
  # yes I know that should be Mail::Mailer, but I don't know its synta
+x
  open MAIL, '|/usr/sbin/sendmail admin' or die;
  print MAIL @_;
  close MAIL;
}
[download]

Assuming FILE is already open and is avalible from there.

This solution also has the advantage of allowing simple and understandable maintainability.