Forum Discussion
Exchange Online Restricts the Number of Dynamic Distribution Groups
Exchange Online is imposing a new tenant-wide limit of 3,000 Dynamic Distribution Groups. Few tenants might be affected, but the question might be asked why Microsoft is limiting DDGs at this point. Is it a cunning plan to prompt people to use dynamic Microsoft 365 groups instead? Or are some tenants abusing DDGs in weird and wonderful ways? Who knows, but the limit applies from early April 2025.
https://office365itpros.com/2025/03/10/dynamic-distribution-groups-limit/
I don't actually think that many organizations (maybe a very small percentage) will be affected by the new limitation. Remember that you need P1 licenses for dynamic Microsoft 365 groups and dynamic admin units... This is just a limit to be aware of, not one to be worried about.
Interesting and disappointing in equal measure. Reminds me of when they dialled back the frequency at which dynamic group memberships were reassessed.
Your idea that it's a precursor to perhaps standardising on Azure dynamic groups for everything does make sense given the previous limit for the Azure dynamic groups was bumped up from 5,000 to 15,000 relatively recently.
But the big, fat caveat is that the Azure dynamic groups have much more than a single application to cover and also includes covering administrative units (i.e. [dynamic group] + [administrative units] must be <= 15,000). Additionally, devices also fall into scope (for Intune) usage-wise.
Granted, 15,000 is more than I can see being used by small-to-medium organisations, but once you get into large government and multinationals, I can't help but immediately reflect on how well the hard-coded limit of 999 global catalog servers went in Windows 2000 (i.e. We've see this all before).
See how it plays out, I guess.
Cheers,
Lain
