[Evolution] Can't send mail using Evolution 1.4.6.mdk

[Peter James <pfjames clara co uk>]

I can't send mail using Evolution 1.4.6. running under Mandrake 10. and KDE.  
I can receive mail OK, but when I attempt to send I get the following error 
message:
"Error while performing operation: Can not send message:  no recipient 
defined:"
The Email recipient is defined in the header of the email, and the pop and 
smtp servers are defined in the configuration set-up.  Can anyone help?  TIA