filter_recipient

Still optional

sub filter_recipient ($$$$$$) {
    my ($recipient, $sender, $ip, $hostname, $first, $helo) = @_;
    if ($sender =~ /^<?spammer@badguy.com>?$/i) {
        if ($recipient =~ /^<?postmaster@mydomain.com>?$/i) {
              return (1, "ok");
        }
        return (0, 'Sorry; spammer@badguy.com is blacklisted.');
    }
    return (1, "ok");
}