"The message could not be sent. The setting for your outgoing email [SMTP] server might need to be configured. To find the server settings for 'tricia/*** Email address is removed for privacy ***', please contact your email service provider.
Server Error: 550
Server Response: 550 Invalid recipient address
Windows Live Mail Error ID: 0x800CCC79
The email address on the error notice is now not in use, although I was not sure at the time I sent the original message. Now the error message keeps occurring and I cannot find a way of deleting it for ever.