On our Exchange 2010 Server I recently created a new user mailbox for a new employee. For some reason this new mailbox becomes disconnected. When it becomes disconnected email to the user bounces: #554-5.2.1 mailbox disabled 554 5.2.1 STOREDRV.Deliver.Exception
bled; Failed to process message due to a permanent exception with message Cannot open mailbox Exchange Administrative Group
Following this article temporarily solves the issue: https://kiransawant.wordpress.com/2013/08/28/exchange-2010-mails-bounce-back-with-mailbox-disabled/
Oddly over this past weekend the mailbox became disconnected late on Friday, tested to not work at 10:00pm. Monday morning the mailbox is working again without any user intervention.
I am starting to go through the servers event logs but wanted to throw this out there incase someone has seen this and has a fix.
Thanks for your input.