Exchange Migrator 1.x
Exchange Migrator 2.x
After migrating with Exchange Migrator, any email sent from the Defense Messaging System outside the Exchange 5.5 organization returns a Non- Delivery Report to the sender.
This received when the Deliv-Ext-Cont-Types field is missing from the migrated mailbox.
To fix the problems with the Non- Delivery Report, you will have to add the Deliv-Ext-Cont-Types field.
To verify that this will take care of the NDRs, add the Deliv-Ext-Cont-Types field to one mailbox and test it by sending an email to it from outside the organization.
Defense Messaging System (DMS) is a messaging system developed for the Department of Defense (DOD). DMS relies on X400 and X500 for routing of mail. For more information, please refer to Microsoft Knowledge Base Article Q231969: XADM: IS/DS Check Does Not Recreate Deliv-Ext-Cont-Types for Mailbox.