05:02 AM PST: Some email users experiencing “Connection Failed” error using SMTP
Some Yahoo! Business Email customers may encounter connection errors when attempting to send email via programs which supports POP, such as Microsoft Outlook or Mozilla Thunderbird.
We are working to resolve this issue in a timely manner. In the interim, customers can access their Yahoo! Business Email account web mail page.
To access your email through the web interface, please visit
http://mail.(domain.tld)
where (domain.tld) is the domain name associated with the Yahoo! Business Email account (see the help center for details).
08:07 AM PST
We are still investigating this issue and will have an update in the next few hours.
10:42 AM PST
This issue has been resolved. You may need to exit and re-launch your mail client to successfully download your mailbox.