I cannot send mail but can receive

[Rachel]

I keep getting this message whenever I try to send an email:

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 'Fw:
Tomorrow Night, Desserts, and a Thank You', Account:
'(e-mail address removed)', Server: 'smtp.att.yahoo.com', Protocol: SMTP,
Server Response: '530 authentication required - for help go to
http://help.yahoo.com/sbc/dsl/mail/pop/pop-11.html', Port: 25, Secure(SSL):
No, Server Error: 530, Error Number: 0x800CCC78


Can someone help? And yes, I have tried changing the SMTP port to 587, and
it did not work. Please help.

 

[Gary VanderMolen [MVP]]

Your immediate problem can be fixed by making sure you have
send authentication enabled.
Go to Tools, Accounts, select that account, Properties, Servers.
Enable the "My server requires authentication" option.

However, in the long run you need to change your ports and SSL setting
to agree with what your provider specifies:
http://www.att.com/esupport/article.jsp?sid=KB401738