07:17 AM PST: Issues connecting to Business Email from Web Mail page
Some Yahoo! Business Email customers may encounter difficulty switching from their Yahoo! Mail web mail page to their Yahoo! Business Email web mail page.
We are aware of this issue and are working to resolve it in a timely manner.
Customers can still access their Yahoo! Business Email web mail page by logging into the mail subdomain of their web site, for example
http://mail.domain.tld
where domain.tld is the domain name associated with the Yahoo! Business Email account. For more information on this alternate method for accessing your Yahoo! Business Email account, please visit our help page.
02:46 PM PST
This issue has been resolved.