Hi Clidd,
Based on
your description, the issue can be caused by the automapping feature. I would
suggest you remove the permission to the mailbox and then grant Full Access
permission to that mailbox. Please attach the “-AutoMapping: $false” parameter
when granting Full Access permission by using Windows PowerShell.
The article
is for your reference: http://support.microsoft.com/kb/2646504.
Best
Regards,
Bruce Zhou
Bruce Zhou