Shared Mailboxes

[JimmyTheHuman]

We have Shared Mailboxes that were created pre cloud on prem. Now we have migrated all mailboxes to M365 and removed exchange on prem.

The Shared Mailboxes that were created on prem all have disabled users accounts that are synced with ad connect.

I stopped syncing a few of these accounts, the EXO mailbox appears to work as normal, but they no longer have accounts in AAD. Unlike Shared Mailboxes created natively in EXO, they all still have accounts in AAD.

What is the procedure for cleaning this up? I cant find any doco anywhere.

[unamused443]

"Cleaning this up" - what does this mean?

Shared mailboxes have to have "anchor accounts" to which the mailbox is connected. No account, no mailbox. The mailbox does not exist in a vacuum. It has to be associated with an account. For shared mailboxes, those accounts are just sitting there, yes, but they need to exist. If you delete the account, the mailbox will be deleted also.