Outlook Mobile now supports delegate access to Exchange Online mailboxes. By granting fuil access to a delegate, they can open and work with a mailbox, and send messages using the SendAS or SendOnBehalfOf permissions. The new feature underscores the advantage Outlook mobile enjoys over other mobile Office 365 email clients.
Exchange administrators are accustomed to looking through mailbox audit logs to find details of events. Those same events are in the Office 365 audit log, so that’s the place to go look for information, like when you want to find out who sent a message from a shared mailbox using the SendAs permission.