An Exchange mailbox related task in OSA[POA] Task Manager fails with the following error message in task output:
There is no mailbox with identifier <mailbox_id>
Using the ID of the problem subscription shown in POA Task Manager for the failed task you check Exchange mailboxes in the customer subscription in POA Control Panel and indeed such mailbox cannot be found.
The customer deleted the Exchange mailbox in question.
After deleting the mailbox and before the task to delete it was actually processed the customer changed some of mailbox parameters. As a result, tasks to change the mailbox were put into queue after the task to remove mailbox and POA mistakenly tried to update mailbox which was deleted already.
Identified as software issue #POA-92655
If you found the completed task to remove the Exchange mailbox then you may be sure that failed task to updated already removed object may be cancelled.
Kindly contact your Account Manager (OR) Pooled Technical Associate[PTA] to trace the status of bug #POA-92655