For Business Email Archive you cannot delete a mailbox you can only deactivate the mailboxes.
Note: Once a mailbox is deactivated the following are true:
- No new emails will have backups or will be archived
- Only the Administrator/Super Administrator will be allowed to access the deactivated mailbox
- User will be denied access
- You can deactivate up to 20% of your total mailboxes beyond which, licenses will be consumed and you will have to pay for it
Follow the steps in this article to deactivate mailboxes :
2) Select the mailbox that you wish to deactivate by clicking on its corresponding radio button
3) Click the De-Activate button
4) A window opens requesting you to confirm that you want to deactivate the selected mailbox
5) Click the Confirm button
The selected mailbox will then be deactivated.
Note: You can re-activate whenever required.