When sending emails in WLM set up for IMAP I am getting the following error? The emails remain in the "Outbox" and then when they are fnally sent they are sent two or three times???

Can anyone provide some assistance as to why this is going on all of a sudden?

Thanks



An unknown error has occurred.

Server Error: 550
Server Response: 550 5.3.4 Requested action not taken; Mail delivery to EXO failed.
Server: 'smtp.live.com'
Windows Live Mail Error ID: 0x800CCC69
Protocol: SMTP
Port: 587
Secure(SSL): Yes