We have a client that has recently migrated from on premise Exchange 2010 to Office 365. I wasn't involved in the migration, more re-configuring Outlook profiles on client machines.
Previously the reported group was a mail enabled security group and did sync with 365.
There are a few distribution groups that whilst work when they're sent to, do not expand when you click the plus symbol next to the group in the To.. field.
I have so far tried:
- Download Address Book in Outlook hasn't worked
- Removed the group completely and recreated a new distro group in Exchange Online
- Removed the group I created in Exchange Online and made it in local AD on their DC
- Forced Azure AD Sync, group appears fine in 365
- Tried to expand the group in Outlook again after deleting the suggestion and entering the full email address, still not working and shows the same error.
Everything I've found online so far hasn't helped and I'm stumped as this affects all users and they'd like to use expand on this 'all staff' email group so they can remove a few users if needed.
Any suggestions are very welcome.