PostMaster Pre-filter module - will pair Delivery Notification Failure message with ticket. This module looks for attachment names a and performs a match against a regexp defined in SysConfig. In case of positive identification of ticket number, Delivery message is paired with given ticket. This module also enables to add custom e-mail headers to outgoing e-mail. Postmaster filter component will check delivered e-mail ant its attachment. When attachment contains custom header (e.g.: TicketNumber), system will merge incomming e-mail with correspondig ticket.