[otrs] Filter emails with empty subject

[Dan Irwin]

I want to return any emails with an empty subject with otrs.

Currently, I have something like this in Config.pm:

    $Self->{'PostMaster::PreFilterModule'}->{'1-Match'} = {
        Module => 'Kernel::System::PostMaster::Filter::Match',
        Match => {
            Subject => '',
        },
        Set => {
            'X-OTRS-Ignore' => 'yes',
        },


However, messages still come through to OTRS and are allocated a ticket 
number.

Should I be doing this filtering with OTRS, or with something else like 
procmail?

Regards,

Dan