The file name of the MDN receipt generated by the adapter.
Filename should contain the name of the file that will be written on the AS3/FTP server. You may use the keyword %AS3MessageId% to refer to the complete AS3 MessageID of the incoming message, e.g.:
If ReceiveMode is set to rAS3Message, MDNFilename must be specified.
This property is not available in the Sender.