[Mimedefang] add_recipient function

[An.H.Nguyen]

I try to add recipient to the below filter code but it does not work. 
Could anyone help please?
Thanks,
An Nguyen

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sub filter_end ($) {
    my($entity) = @_;

    # No sense doing any extra work
    return if message_rejected();

      my $recip;
      if ($recip =~ m/\@subz\.domainz\.edu>?$/i) {
      add_recipient('myemail at domain1.com');
      }

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