"Search for messages from..." doesn't work

This week's problem...

When I use the link to "Search for new messages from" -- open a message, click on sender name then click the link indicated -- there are no results.    AFAICT, this started a few days ago.   What's the deal?

Note:   One of the constantly annoying issues I have with ATT is its non-support of the actual e-mail application.    The Yahoo! e-mail link for "E-mail Support" is directed to ATT -- which repeatedly tells us that it is not responsible for the actual e-mail application.    If you aren't going to support the application, why are you hijacking the link?