Yes you can delete mailbox data stored in the online archive.

1. Open archive mailbox - delete folders/items which is the fastest way to delete
2. Delete data using retention policy
3. Hard delete if requirement is to delete all online archive data - unassign the license and Microsoft will soft delete the archive
4. eDiscovery purge option

Hope this give you more info.

Hi Thao_Dao_Phuong​, you have three options for this:

1. Use Outlook to open the archive mailbox and manually delete the data.
2. Delete the archive mailbox altogether (and then create a new, empty one if you need archiving).
3. Use Microsoft 365 retention policies to delete data in the archive based on age (see https://learn.microsoft.com/purview/set-up-an-archive-and-deletion-policy-for-mailboxes for details).

Hope this helps!

Hi Thao_Dao_Phuong​, you have a couple of options for doing this:

1. Use Outlook to open the archive mailbox and delete the data manually.
2. Delete the archive mailbox altogether (and then provision a new one if you still need archiving).
3. Use Microsoft 365 retention policies to delete data after a certain age. See https://learn.microsoft.com/purview/set-up-an-archive-and-deletion-policy-for-mailboxes for details.

Hope this helps!