I can recieve but not send e-mails

[Greg]

This is a yahoo account that had been working till this morning.

It starts with the "log onto network" page, then if you hit ok it comes

 

[Roady [MVP]]

Do you have a virus scanner installed which integrates itself with Outlook?
Uninstall this integration part of your virus scanner and try again; you'd
still be sufficiently protected by your on-access scanner part of the virus
scanner. For more details see;
http://www.msoutlook.info/question/20

This is a yahoo account that had been working till this morning.

It starts with the "log onto network" page, then if you hit ok it comes

back. But if you hit cancle you get this error.
Error: log on to incomming mail server (POP3): Your e-mail server rejected
your log in. Verfy your user name and password in your account properties.
Under tools, click Email Accounts.
The server responded; -ERR [AUTH] invalid user/password

I have tried changing my user name & password. I have gone to "more
settings and verified everything and nothing works.