After a cross-forest Ex2003 to Ex2010 migration, some users are unable to share their calendars with other users. UserA using Outlook 2007, cannot share their calendar with UserB. The error message UserA gets is: Calendar sharing is not available with the following entries because of permission settings on your network I set up a new Outlook profile using Outlook 2003 for UserA, and they were able to share their calendar and add UserB as a reviewer. Haven't tried setting them up with a new profile on Outlook 2007, will do that tomorrow. I did check the user to ensure they were being updated by the 2010 email address policies. Also verified UserA's calendar and permissions weren't corrupted using ExFolders. User C with outlook 2007 can share his calendar as usual, but his mailbox wasn't migrated cross-forest and isn't a linked mailbox- it's a normal Ex2010 mailbox. The migrated mailboxes are linked to their original Ex2003 user account in the old forest. Full domain migration will take place at a later time. Any other things to check? Thanks

Hi, Whethe the SID history was stamped on the migrated account? Please understand that the Sid history holds security identifier information of the orginal account which can access the original resource. If the sid history was not migrated to the target account, the original permission which you granted will not work. Thus, you need to remove the permission and re-add it. Thanks Allen