One or more mailboxes associated with the email server profile {0} that is configured with server-to-server authentication ...

One or more mailboxes associated with the email server profile {0} that is configured with server-to-server authentication have been disabled for synchronizing appointments, contacts, and tasks because their email addresses need an approval by an Office 365 administrator. After the mailboxes are approved, enable them for synchronizing appointments, contacts, and tasks.