I recently deleted the mailbox of a an old receptionist in our organization, after migrating from Exchange 2000 to 2007. Shortly after this many users complained that they were getting message delivery errors when sending out or changing meeting requests. My guess itthat thisuserhas always been receiving these messages,but now that the mailboxhas been deleted theserver cannot find the recipient for the automatically genereated messages.I have since when through the most of our mailboxes using the cmdlet get-mailboxpermission and manually removed the user's permissions from the mailboxes that Ifound them on. The issue occurrancehas decreased, but still seems to be there. Is there a way to query exchange for all permissions associated with that old account? Or, do anyone have any ideas what else maybe causing this issue? Thanks, Miles

Hello Miles, You dont have to check mailbox permission. This normally happens when somebody has given delegated permission to your old receptionist on their mailbox with an option Delegate receives copies of meeting-related messages sent to me to manage their calendar and all meeting requests/changes go to her but that id is deleted so meeting organizer gets NDR. Reference: Allow someone else to manage your mail and calendar http://office.microsoft.com/en-us/outlook/HA100750811033.aspx You need to find and remove the old receptionists id from the delegates manually from the mailboxes, whoever has given delegate access to her on their calendar.