Apr 16 2020 11:00 AM
Apr 16 2020 11:00 AM
I have a ticket open with Microsoft about this, so just posting here for comment from others.
Customer has all user mailboxes in on-premises Exchange, hybrid is not configured.
A retention policy applied to all users for Teams Chat only, configured to not retain, but delete after 7 days.
This policy was created and applied around 25th March.
As of today, some users still still chat messages from 2019. Nothing seems to have been deleted for most of them.
I did see chat messages back to 2019, but then when I signed out of the Teams app, and signed back in, I now only see chat messages from 3rd April ('it's good, but it's not right').
No cloud mailboxes for users, means 'shadow mailboxes' have been created for each user - can be checked by running 'Get-MailUser' cmdlet against EXO.
These shadow mailboxes contain the chat messages (for the purposes of retention - I know about the chat service) - but for most of the users, the Managed Folder Assistant will not run, because the shadow mailbox is smaller than 10MB (the threshold for running MFA) - so the chat messages are not purged after 7 days.
Sometimes a shadow mailbox reaches 10MB, then the MFA runs, clears some chat messages, the size drops below 10MB, then does not run again the following day??
Or does the MFA never run until the mailbox is 10MB, then it always runs daily even if the mailbox slips below 10MB again?
Thoughts / comments anyone?
Apr 17 2020 07:46 AM
I have a similar environment where Exchange is on premise, not hybrid. I created a policy and did not see the effects until I logged out of Teams and then logged back in. I continue to see other oddities that suggest there are a lot of caveats that appears to be at play.
May 07 2020 01:53 PM
Were you able to get a resolution to this? We are seeing the same problems.
May 07 2020 02:09 PM
Yes, eventually chats older than my policy date were removed. I was testing so I had the policy set to any chat older than 7 days, delete, do not retain. It took about 3 days before I started seeing the policy take effect. I also noticed there was a day or two lag, meaning, i could still see chats from 8 or 9 days before, those eventually were deleted the next day or thereafter.
May 21 2020 05:39 AM
Jul 28 2020 12:08 PM
@Rob Ellis we are having the exact same issue. We have a hybrid server configured(2019) as well as a adconnect server. But none of the teams messages are being deleted.
Jul 30 2020 10:28 AM
To close this one down, from my perspective at least - some more info:
MS confirmed that in our scenario, these cloud mailboxes (referred to as 'Componentshared only' mailboxes by them) are not processed by MRM / MFA - they are processed by a different job, called ComplianceJobAssistant.
The ComplianceJobAssistant does not have the 10MB limit like the MRM / MFA does - so the amount of chat messages is not relevant.
They think that it was simply the case that when we enabled the retention / deletion policy, it took multiple runs of the ComplianceJobAssistant before it had completely got up to date on all the relevant mailboxes, because in some cases it would have needed to clear down months of older messages.
We've had various users check, and we have had no further reports of any issues, so we expect everything to be fine from now onwards, because all the jobs have caught up, and are now in a steady state of operation.