Iam adding permissions to a linked mailbox with te following commandlet: Add-MailboxPermission -Identity "xlocal.local\mvanburen" -User "x.nl\mwisse" -AccessRights fullaccess -DomainController $dc -InheritanceType all -AutoMapping:$true as you see we have have a domain with the netbios name xlocal and x. If I complete the script it resolves the xlocal.local mailbox insted of the x.nl user. The local domain is a 2008/exchange 2010SP2 and the x.nl is a 2003/ exchange 2003Sp2 domain. there is a 2 way trust between them on forrestlevel. Any body any sugestions resolving the issue? With Kind Regards, Lon

So you're clear that in your example, xlocal.local\mvanburen is the mailbox's user account and x.nl\mwisse is the user who is to get rights on the mailbox, right? Just a wild-ass guess: Did you do a interforest user migration and give xlocal.local\mvanburen the SID history of x.nl\mwisse?Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."

If I complete the script it resolves the xlocal.local mailbox insted of the x.nl user. Hi Leon, Any updates? Seems like you have the same issue as the following thread: add-mailboxpermission doesn`t work cross forest http://social.technet.microsoft.com/Forums/en/exchangesvrgeneral/thread/a7b86f2d-9568-40ab-8a03-d9cea48f256d Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.Frank Wang TechNet Community Support

If I complete the script it resolves the xlocal.local mailbox insted of the x.nl user. Hi Leon, Any updates? Seems like you have the same issue as the following thread: add-mailboxpermission doesn`t work cross forest http://social.technet.microsoft.com/Forums/en/exchangesvrgeneral/thread/a7b86f2d-9568-40ab-8a03-d9cea48f256d Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.Frank Wang TechNet Community Support

Hi Leon, Any updates?Frank Wang TechNet Community Support