How does Exchange Migrator handle conflicting Distribution Lists?
Exchange Migrator 1.x
Exchange Migrator 2.x
Distribution List Collision Handling
When you migrate a distribution list, Exchange Migrator checks to see if the source distribution list conflicts with a target distribution list. If Exchange Migrator detects a conflict, it applies the collision handling option specified in the migration options wizard to the source object.
When it applies collision handling, Exchange Migrator uses the same criteria for distribution lists as for mailboxes. For more information about collision handling criteria, see "Mailbox Collision Handling".
The following NetIQ KB article references the Mailbox Collision Handling section from the User Guide:
How does Exchange Migrator handle conflicting mailboxes?