Retention policy MRM not working

Question

I have created a new MRM Retention Tag with the following details

1 day delete, Type is "Deleted Items" with retention period set to 1 day and retention action is "Delete"

This tag is attached to the default MRM Policy.

I have enforced this via ManagedFolderAssistant, however this only seems to have worked with 1 month delete and not any items that are in the Deleted Items folder for more than a 1 day.

Policy has been applied to the user, other policies have taken affect but not the new tag that I have created

am I missing something? Below are the details of the retention tag

This hasn't worked, so I have created a Retention Policy within Purview

If the functionality from the Default MRM and retention tags has been deprecated - is there any other method which has replaced this apart from the above as it's not very granular - unless we, do it manually on the user's mailbox.  

And that's if the policy shows in Outlook (Desktop) + OWA to be applied, however this would be very tedious. 

Answer 1

Two things. First, you cannot really have a "1 day" policy in Exchange Online, as the MFA works on a 7-day workcycle. So even with "1 day delete" tag, you can expect messages to be removed with delay.

Second, the Deleted items folder is treated differently, due to some convoluted logic Microsoft came up with years ago. Long story short, you need to either create a new policy, or rename the default one. I have more detailed explanation here: https://www.michev.info/blog/post/5868/make-sure-deleted-items-are-automatically-removed-from-microsoft-365-mailboxes

Lastly, you should not use Purview retention policies for this scenario, they cannot target specific folders.