The problem with Internet Explorer and Yahoo Mail is not officially documented.
I’m a computer tech by trade. I found the fix by trial and error.
I was having the same problem with my Yahoo Mail account. When I switched to FireFox, the IE problem went away.
Other browsers may work, too.
Glad to see I am not the only one experiencing this. I hate to trade out the browser and work around a bug, so I will probably transition to gmail.
The very fact that the wrong email can be opened now leads me to question whether other people could open mine.
Am amazed that this issue does not get more press.