Interested in content regarding Office 365 and Distribution List Migrations. The following table of contents links to relevant articles regarding the Distribution List Migration Module Version 2.
- GitHub Repository
- Power Shell Gallery
- Part 1: Introduction to the Distribution List Migration Module Version 2.0
- Part 2: Distribution List Migrations Version 2 – Part 2
- Part 3: Preparing to use the distribution list migration v2 module
- Part 4: Using the distribution list migration module v2 for simple migrations.
- Part 5: Retaining the original distribution group post migration…
- Part 6: Gathering advanced dependencies for a group to be migrated.
- Part 7: How does the module track distribution lists that have been migrated?
- Part 8: Enabling hybrid mail for migrated distribution lists.
- Part 9: Performance updates and enhancements.
- Part 10: Distribution list migrations version 2.0 – updates.
- Part 11: Improvements in error handling in version 2.4.8.x
- Part 12: Announcing multiple migration machine support
- Part 13: Enabling support for partially mail enabled distribution groups.
- Part 14: Enabling hybrid mail flow post migration.
- Part 15: Enabling migration support for non-synchronized groups.
- Part 16: Mail flow issues with centralized mail transport enabled and migrated distribution groups.
- Part 17: I need assistance with the migration module, have a suggestion, or want to request a feature.
- Part 18: New handling of recipient restrictions assigned to the migrated distribution groups.
- Part 19: New handling of distribution group creation during migration to eliminate ambiguous references.
- Part 20: Adding a new method to verify the distribution list is directory synchronied.
- Part 21: Preparing for deprecation and disablement of basic authentication.
- Part 22: The end of basic authentication in Exchange Online…
- Part 23: Collecting telemetry for performance improvements and usage statistics.
- Part 24: Issues encountered with large distribution list migrations.
- Part 25: Large distribution list migrations and code enhancements to increase performance and reliability.
- Part 26: New handling of nested distribution groups in multiple distribution group migrations.
- Part 27: Increasing the performance of multiple distribution list migrations.
- Part 28: Implementing exception codes.
- Part 29: Implementing the ability to migrate directly from on-premises distribution lists to Office 365 Unified Groups.
- Part 30: Converting a cloud only distribution list to an Office 365 Unified Group.
- Part 31: Enabling support for interactive authentication and single list migrations.
- Part 32: Enabling support for a custom routing domain.
- Part 33: Testing a distribution list pre-migration.
- Part 34: *IMPORTANT* Preparing for MS Graph Implementations
- Part 35: Improved handling for mailbox folder permissions, full mailbox access permissions, and send as permissions.
- Part 36: YouTube Tutorial – Introduction to Distribution List Migration 2.0 Module
- Part 37: YouTube Tutorial – Planning distribution list migrations with the Distribution List Migration 2.0 Module
- Part 38: Enabling support for migrations with pre-defined name prefix or suffix.
- Part 39: Implementing improved error handling and error cleanup.
- Part 40: Offering a new alternative for nested group migrations…
TIMMCMIC 
Impressive amount of work! I’ve gotten lost in the documents on dealing with nested groups. We have some very large trees with many circular nesting of groups going on. Some even 3 or 4 DL circles and all in the same tree. structure. It doesn’t seem this will work.
LikeLike
Nick:
So here is how nesting works. When you specify a group of SMTP addresses to be migrated with start-multipleDistributionListMigration if a parent is tried before a child then the parent is put in a retry queue. If the child was included in the migration set originally – then the parent is retried after a full pass is done.
So take this structure
Parent1
Child1
Child1A
If all three were specified Child1 and Parent1 would fail. Parent1 and Child1 would be retried. On the second pass parent1 would fail and be retried because Child1 was in the set.
Now if you have something like this.
Parent1 contains child 1
Parent2 contains child2
Child2 contains child1 and child1 contains child2 this will not automaticlly retry since there is no a circular dependency. You’d have to remove child1 or child2 from each other and do a migration – then add the contact back that is created.
Circular nesting can certainly bring about challenges.
LikeLiked by 1 person
Pingback: Complex Identity Migrations & Microsoft using PowerShell | Practical365
Pingback: Office 365 – Distribution List Migration – Version 2.0 – Table of Contents | TIMMCMIC
Pingback: Restore Deleted Groups Only Possible for Some Group Types