You could check the Message-ID: field in the incoming message against a search of the current tickets in the OTRS postmaster code, but that would be very time-consuming for any volume of mail. I’d go with Gerald’s comment: tell them not to do that, and deprecate one of the two addresses and remove it in a systematic way (or turn one into an alias of the other if for some good business reason both still need to exist).
---------------------------------------------------------------------
OTRS mailing list: otrs - Webpage: http://otrs.org/
Archive: http://lists.otrs.org/pipermail/otrs
To unsubscribe: http://lists.otrs.org/cgi-bin/listinfo/otrs