Occasionally, the Exchange Gateway encounters a message that it cannot process, either because the message file has been damaged or because the recipient is not a user that is recognized by the gateway. You can use the /badmsg switch in the Exchange Gateway startup file to indicate how you want the Exchange Gateway to handle messages that are damaged or undeliverable.
By default, bad messages are moved to the domain\wpgate\exchange\gwprob directory (the equivalent of /badmsg-move). If you want to take a look at bad message files, you can have the gateway send the bad message files to the postmaster using /badmsg-send. If you do not yet have a postmaster, see Section 8.6, Establishing Gateway Administrators for setup instructions.
If you do not want to do anything with bad messages, you can have the gateway delete them immediately using /badmsg-neither.