Problem with outgoing mail

[SMH]

The message could not be sent. The authentication setting might not be
correct for your outgoing e-mail [SMTP] server. For help solving this
problem, go to Help, search for "Troubleshoot Windows Mail", and read the
"I'm having problems sending e-mail" section. If you need help determining
the proper server settings, please contact your e-mail service provider.

The rejected e-mail address was '(e-mail address removed)'. Subject
'Divided+Microwave+Plates+With+Lids+from+Collections+Etc.', Account: 'Windows
Mail', Server: 'plus.smtp.mail.yahoo.com', Protocol: SMTP, Server Response:
'553 From address not verified - see
http://help.yahoo.com/l/us/yahoo/mail/original/manage/sendfrom-07.html',
Port: 465, Secure(SSL): Yes, Server Error: 553, Error Number: 0x800CCC78

 

[Gary VanderMolen [MVP]]

So did you do as the error message advised you to do,
go to
http://help.yahoo.com/l/us/yahoo/mail/original/manage/sendfrom-07.html
and follow the procedure to verify your @hotmail.com email address?
Yahoo won't let you send from an unverified address.