A user was complaining he can’t send meeting request or some emails to specific users. The user gets bounced mail (NDR) and NDR has the following error message.
This message could not be sent. Try sending the message again later, or contact your network administrator. The client operation failed. Error is [0x80004005-0x0004b9-0x000501].
I do realize I moved bunch of mailboxes and the user complaining he can’t send mails to those moved mailboxes. When I try to track the message using Exchange console, I don’t see this mail hitting Exchange at all. So this is Outlook specific issue. It became clear user’s Outlook didn’t get the latest mailbox move information (Offline Address Book). I informed user to download the Outlook Offline Address Book manually (Outlook: Tools –> Send/Receive –> Download Address Book and click OK on the dialog box).