Adding an administrator’s mailbox permission allows further troubleshooting and advanced Mailbox management.
To add an administrator’s mailbox permission, open the Office 365 Admin. Search for the user’s mailbox on the search bar. Once found, click the user’s “display name” to open the mailbox’s attributes.
Then, under Mailbox permissions > Read and manage emails to this mailbox: search for your own admin account. Once found, add it and click “save” at the bottom of the page.
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