[Mimedefang] bypassing mimedefang for single user

[Muhammad Talha]

Dear all

i am newbie in configuring mimedefang-filter .one our client bussiness such
that he gets lot of .exe and zip file everyday
i want to disable mimedefang for single user. i read man mimedefang-filter i
have to use option filter_relay

Is this sytax is correct

sub filter_relay {
  my($ip, $name, $helo) = @_;
  if ($helo =~ /mydomain.com/i) {
    if ($ip ne "192.168.1.200") {
          return('ACCEPT_AND_NO_MORE_FILTERING');
            }
  }
  return ('CONTINUE', "ok");
}

1)  What if my client do not have static ip . ??
2)   Can i bypass mimedefang using email address , Should i have to use
filter_sender or filter_recipient ??

Thanks in advance

Regards

Muhammad Talha