Hello - just starting today, I can not send out email in Windows Live.  I receive email fine, just wont send it out (it is 'stuck' in the Outbox).  The warning message is:

"The message could not be sent because the server rejected the sender's email address. The sender's email address was *** Email address is removed for privacy ***'.

Subject 'test1'
Server Error: 550
Server Response: 550 5.1.0 <xxxxx@charter.net> sender rejected
Server: 'mail.charter.net'
Windows Live Mail Error ID: 0x800CCC78
Protocol: SMTP
Port: 25
Secure(SSL): No

I can send out email to my from my online server email account, so it's not the servers fault on this.

THANK YOU very much for your help!

PS....The 'sender's email address' that is being rejected is mine