What is the cause of this? Pls explain..
Thanks..
Delivery Status Notification (Failure)
This is an automatically generated Delivery Status Notification.
Delivery to the following recipients failed.
xxxxxxxxxxx@hotmail.com
Reporting-MTA: xxx;xxxx-xx.hotmail.com
Received-From-MTA: xxx;xxxx-xx.hotmail.com
Arrival-Date: Sun, 09 Mar 2008 22:04:06 GMT
Final-Recipient: xxxxxx;xxxxxxxxx@hotmail.com
Action: failed
Status: 5.5.0
Diagnostic-Code: smtp;550 Requested action not taken: mailbox unavailable