I am facing the issue while hiding the shared mailbox in Office 365, as this we required because there is another mailbox in Office 365 that is havign same Display name and due to this it is showing GAL.
So we need to hide the Unused shared Mailbox. So while hiding it. We are getting below error :
"The operation on mailbox failed "John Smith" because it's out of the current user's write scope. The action 'Set-Mailbox', 'EmailAddresses', can't be performed on the object John Smith because the object is being synchronized from your on-premises organization. This action should be performed on the object in your on-premises organization."
I also want to let you know that we are currently in Mid-migration and we are in Cross-premises Environment
Having Exchange 2010 and Office 365
any suggestion will be greatly appreciated.