Your message did not reach some or all of the intended recipients.
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].
Possible causes and solutions:
- This error can be caused by intermittent network problems in which case simply resending the message should work.
- Outdated DNS entries on the cache in which case flushing the DNS cache should do the trick. To clear up the cache start the command line utility and type ipconfig /flushdns and hit enter. That should clear the cache so when you resend the email the recipient's address will be resolved again and it should work fine.
- Local address book entries are out of sync with the corresponding server entries. In this case removing the particular address from your local address book should resolve the issue. In Outlook 2010 to remove the entry from your local address book do the following: start typing the address in question on the address bar of a new email, a drop down appears with all matching names; move the mouse over the address of interest and you will see a red "x" appear on the side of that name - click on it to remove that entry.