How long will items be kept in an In-Place Archive with Microsoft's Default MDM Policy?

I did a lot of research to find an answer to this question, but without luck so far.

The situation is as follows:

• Exchange Online with EO Plan 1, E3, and E5 licenses
• No modifications were done to Microsoft's default MDM Policy
• Enabled Personal Archive for each Mailbox in EAC | Recipients | Mailboxes

The "Default MDM Policy" has a Retention Tag named "Default 2 year move to archive". That means each Item > 2 years old will be automatically moved to the In-Place Archive by the Managed Folder Assistant.

I also know that all Retention Tags of type "new tag applied automatically to the entire mailbox (default)" will apply to a user's mailbox and his In-Place Archive.

Means, if I would add another "default"-Tag to the Default MDM Policy and set it to "Permanently delete" after 7 years, all Items > 7 years old (either in the User's mailbox or his In-Place Archive) would be deleted.

But what happens to items in In-Place Archives, when I only have the "Default 2-year move to archive" Tag? I mean, when I do not modify the "Default MDM Policy".

Will Exchange keep In-Place Archive Items forever, or am I missing something? Also, I know I could have some kind of Hold on some/all items, but I have it not configured.

Solution 1:

According to my research, there are some tags in the default retention policy, a DPT，a RPT, 9 PTs.

The Default MRM Policy doesn't include a DPT to automatically delete items (but it does contain personal tags with the delete retention action that users can apply to mailbox items). If you want to automatically delete items after a specified period, you can create a DPT with the required delete action and add it to the policy.

For more details: Default Retention Policy in Exchange Online and Exchange Server