We upgraded our server to enterprise edtion this weekend and applied SP3 for exchange 2000, and I now have a problem. When a user attempts to assign a task to someone else, they get the message of : you do not have permission to send the message on behalf of the specified user I have tried to give that user full mailbox rights, send as rights, and send on behalf rights, but it still comes back as failing. Is this something added in SP3 to block send as permissions? Is there a workaround so the users here can assign tasks to each other? Rob