When you delete an item from Deleted Items folder, there is a way to restore it from Personal Archive. Here is what you need to do:

  1. Login to My Services using your email address and mailbox password.
  2. Click Email Archiving > Manage Your Archive.
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    My Services
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  3. Click Advanced Search and find the deleted message using any of the search criteria.
  4. Highlight a message and click Recover.
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  5. The message will be delivered into your Inbox with an original timestamp.

Note: When exchange mailbox or the whole AD user is deleted, the data from the mailbox remains in the archive and can be accessed by a search admin.