554 Transaction Failed: Cannot send message due to possible abuse

When I use outlook to send a message or reply to a message I am getting a

554 Transaction Failed:  Cannot send message due to possible abuse;  please visit http://postmaster.yahoo.com/abuse_smtp.html for more information.

 

 

I can't believe this is a Yahoo error because I can log into my yahoo account and send just fine.  I only get this error when trying to send from my outlook.  (I am receiving emails though)

 

I have windows 7

 

Any ideas?  I have scoured the internet trying to find any answers but so far I don't see anything about this particular problem.

 

Julie