Exchange Online Retention Policy Not Applying: A Read-First Purview vs MRM, Distribution, and Scope Triage
Helpdesk: "Compliance turned on a Delete after 3 years retention policy for all mailboxes in Purview last week. Mail from 2019 is still sitting in people's Inboxes, and Outlook still shows the old Default 2 year move to archive tag. Can you delete the policy and recreate it, and run the Managed Folder Assistant on everyone?" An hour later a second ticket: the shared Accounts Payable mailbox was…
A helpdesk ticket revealed confusion around an Exchange Online retention policy not applying to mailboxes in Outlook. The user had a 3-year retention policy set by compliance, but still saw old emails and a 2-year move to archive tag. Another ticket showed a shared Accounts Payable mailbox not showing any change after being added to a different retention policy last month.
The issue with Exchange Online retention policies is that they rely on two separate systems within the same portal: Microsoft 365 retention policies and Exchange MRM policies. A common cause of the problem is a mix-up between these systems or a policy that hasn't fully propagated.
To troubleshoot, start by confirming which system the issue is related to - either the Microsoft 365 retention policy via Purview or the Exchange MRM policy/labels. Then, check the policy's health: is it enabled, does it have rules, and is it set to Enforce mode? If not, the policy won't take effect.
Next, verify the distribution status of the policy. If it's pending or has errors, give it time - Microsoft recommends allowing up to seven days for distribution to complete. If the distribution status looks good, move on to checking the scope of the policy.
Ensure the mailbox is included in the policy's scope. For static policies, static groups are expanded at configuration time and don't automatically update when membership changes. Adaptive scopes, on the other hand, run once a day and may take up to five days to populate.
Also check if the mailbox meets the minimum requirements: it needs at least 10 MB of data and must be processed by the Managed Folder Assistant. Hold GUIDs on the mailbox or organization-wide holds can also interfere with the retention policy.
Finally, consider other potential conflicts like existing retention labels, litigation holds, or eDiscovery holds. Remember that retention policies take precedence over deletion policies. After confirming all these factors, wait up to seven days for the retention settings to take effect, and remember that expired items are permanently deleted within 14 days after the retention period ends.
Written by urgent.news from Dev.to's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
