I am unable to unregister a mailbox from the Auto Accept Agent using RegisterMailbox.vbs /u:firstname.lastname@example.org. I receive a Windows Script Host message box "Invalid parameters". I'm pretty sure I have the syntax correct and I'm certain I have entered the correct SMTP address. Also, I verified the account is registered using the MailboxStatus script.
OS is Windows Server 2003 Ent SP1 with Exchange 2003 SP2.