We're trying to set the Send-As ExtendedRight to a user for a shared mailbox. We're on Exchange2010, so everything needs to use remote powershell. We are also using c# to execute the powershell.
We are able to add AccessRights using Add-MailboxPermission, but SendAs is now required to be set using Add-ADPermission. Unfortunately, when executing Add-ADPermission, an exception is thrown (the exception message is the title of the post). The part that baffles me, is I can run this command locally on the exchange server in which we're connecting to with remote powershell. So it's definitely loaded, and the fact that the server we're connecting to is an exchange server makes that a given. I get this same error when trying to run Remove-ADPermission. However, Get-ADPermission works fine, and returns the values I expect. Additionally; Enable-Mailbox, Set-Mailbox, Add-MailboxPermission, Get-MailboxDatabase, Get-ADPermission all work.
What am I missing to make Add/Remove-ADPermission to work over remote powershell?
Please see the following for a recap of a previous thread --> http://social.technet.microsoft.com/Forums/en/ITCG/thread/6d7bfed6-6ed8-4290-a999-df673471ea9a