Mailbox not becomeing inactive/disconnected after license removal

Question

When a user has a retention/hold policy applied to them it appears that you can not remove their EXO license or mailbox as long as the user object is present. If you do you wind up getting the following error when you look at the user object in the M365 interface:

"Exchange: An unknown error has occurred. Refer to correlation ID: cb54c6b0-d27c-4dfd-b771-ba50eb7fd3e6.; Exchange: An unknown error has occurred. Refer to correlation ID: cb54c6b0-d27c-4dfd-b771-ba50eb7fd3e6.;"

Not only that but the mailbox continues to appear in the "Mailboxes" tab of the EXO admin interface, GAL and can still receive mail.

This is true whether you just remove the EXO feature or remove the entire license.

This doesn't make any sense to me. If I deleted the user object from O365 then in 30 days the mailbox would become inactive. Then if you recreated the user two months later it would build a new mailbox for the returning user and there would be two mailboxes, one active and one inactive (I know this is bad for discovery but that is how it would work).

It is a major problem if you can not cause a mailbox to become inactive by delicensing the user. It would seem to be a bug to me. I'm dealing with a situation where a client licensed 10,000 users with every feature even though they didn't intend to use EXO with those users. Because there is a 7 year retention policy on all data we now have a problem when we try to remove the EXO feature from these accounts. It will not put those mailboxes into an inactive state! (I know we could remove the hold but that has its own compliance problems and this doesn't seem to me to be the way it should work)

Answer 1

It's not a bug and is clearly documented in the corresponding articles. The only supported method to make a mailbox inactive is by removing the corresponding user object. Removing the license does not trigger the same workflow, moreover it puts you in a license violation.
In your case, you should exclude those mailboxes from any and all retention policies/in-place/discovery holds, then do the delicensing operation. Alternatively you can try opening a support case and ask to get the mailboxes removed via Disable-Mailbox and the -IgnoreLegalHold switch, which unfortunately is no longer available to us (https://learn.microsoft.com/en-us/office365/troubleshoot/holds/ignorelegalhold-not-available).

Answer 2

Hi @Rob Axelrod

Agree with what michev said above, we can't make a mailbox inactive by removing the license.

The official document introduces the below information:

Making a mailbox inactive involves two steps: 1) placing the mailbox on Litigation Hold or applying a retention policy to it, and 2) deleting the mailbox or corresponding user account. After the mailbox is inactive, its contents are retained until the hold or retention policy is removed.

And if you want to Delete an inactive mailbox, the official document also indicates that we should remove the hold from the inactive mailbox

Referring to the way to contact Online support here.

---

If an Answer is helpful, please click "Accept Answer" and upvote it.

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.