Exchange Transporter Not allowing impersonation

I run this command:

Add-ADPermission -Identity Server01 -User company\adminacct2 -Extend
edRights ms-Exch-EPI-Impersonation

And I get back this result:
I get back this

Add-ADPermission : There are multiple objects matching the identity “Server01”. Please specify an unique value.
At line:1 char:17
+ Add-ADPermission <<<< -Identity Server01 -User company\adminacct2 -ExtendedRights ms-Exch-EPI-Impersonation any ideas why it think there are multiple objects matching the server id? I've also asked / added it to here http://forums.microsoft.com/technet/ShowPost.aspx?postid=3708450&isthread=false&siteid=17&authhash=ced0a5b24d9c62e82d5b91f3230554b21fccd10a&ticks=633535236456849297 Thanks in advance