Retention policy to delete items older than 30 days in "Deleted items" folder

Kavindu Dayananda 76 Reputation points


We have a requirement to create a retention policy to delete mails/items older than 30 days in "Deleted Items" folder.

So we have created a retention policy for "Deleted Items" default folder as per below.

Type : Deleted Items
Action : Permanently Delete
Retention Period : 30 days

Then we have created a policy including this tag and applied it to a user mailbox. After applying it to the mailbox we also ran "Start-ManagedFolderAssistant" for that mailbox.

However still mails which are older than 30 days in "Deleted Items" aren't deleted from the mailbox.

Then we created another tag (for testing) targeting "Inbox" (default) folder with same retention period. Followed same steps which we did for previous tag and it started deleting mails from "Inbox" folder. So it works for "Inbox" folder but not for "Deleted Items" folder.

After doing some research on internet it seems that this works differently for "Deleted Items"

Can someone explain what i'm missing here or what I need to do, in order to fulfill my requirement?

Exchange Server Management
Exchange Server Management
Exchange Server: A family of Microsoft client/server messaging and collaboration software.Management: The act or process of organizing, handling, directing or controlling something.
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Accepted answer
  1. JeffYang-MSFT 6,241 Reputation points

    Hi @Kavindu Dayananda ,

    Looks like your situation is quite normal and it is an expected behavior. As the document said, the retention age is calculated differently for items in the Deleted Items folder and items not in the Deleted Items folder.

    I did the same test in my Exchange Server 2016, created a Retention tag like yours, added it into the Retention policy and assign to a test user.

    Tests result shows that:

    1. For the existed items in "Deleted items" folder, they will not be deleted immediately. The retention age is calculated from the time you assign the Retention policy and emails will be expired and be deleted after 30 days. Their expire information would be displayed in the email messages like below:
    2. For those new items you move to the "Deleted items" folder. When emails were moved to Deleted Items, they were tagged on that date. So original date of email received was ignored. And you could also check their expire information in their email message.

    So, based on all the test results above, we may could be able to infer that all the items in your "Deleted items" folder will be expired and be deleted after 30 days. I tried some research but failed to find any available methods to automatically remove emails in "Deleted items" folder based on the original date of email received. While, from the perspective of the Outlook client, you could try the “Auto Archive” feature to fulfill your requirement.

    Hope these could be able to help.

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  1. Vasil Michev 94,441 Reputation points MVP

    The Deleted item folder tag is ignored when you are using the default MRM policy. This is "expected" as Microsoft changed the behavior few years back... although they conveniently forget to mention it in the documentation.

    You need to either create a new policy with such tag and assign it to users, or rename the default policy. Other than that, wait.
    For example, in my tenant I have created a new tag "Deleted Items 30 days", with type DeletedItems and retention age 30 days. Added this tag to a newly created MRM policy and assigned it to the mailboxes. As a result, items in the deleted items folder are removed after 30 days.