[otrs] using email to close otrs tickets

Hello all, I am using otrs version 2.1.2. I would the ability to close tickets via email. I would like to have a filter that finds either: CLOSED or RESOLVED as the first word in the subject line, and have otrs close the ticket. Is there some way to do this? I have tried using the postmaster filter with these settings: Match: Header 1: Subject Value: CLOSED Set: Header 1: X-OTRS-State Value: closed successful But this does not seem to work. Janet