I can not send email messages on WLM.  However, I can receive messages.  The messages are going to the out box.  WLM was working fine since I purchased the Dell computer in April 2012.  The problem started today, 8/29/12.  The email messages are one or two words in length.  I can send and receive messages on my COX webmail account.  The following is the error message I receive:

This message could not be sent because its size exceeded the server's limit. You can use the option, located in Tools | Accounts | Properties | Advanced, to break messages into smaller parts.

Subject 'Fw: Dear Subscriber'
Server Error: 552
Server Response: 552 5.2.0 sojs1j00B2dT6vs01ojs5f This message was undeliverable. This message has been found to be a potential spam message, and has therefore been blocked. Please visit http://ww2.cox.com/coxagainstspam for more information.
Server: 'smtp.west.cox.net'
Windows Live Mail Error ID: 0x800CCC6D
Protocol: SMTP
Port: 25
Secure(SSL): No

Can you help me.

Thanks.