emails no longer identified

I have no way of knowing who sent me any email - all the information Thunderbird gives is subject and date and a series of digits - usually 5 but sometimes fewer. Often I know the subject, but often I don't and although I don't get much spam (D.G.) I'm always afraid to open unidentified stuff.

I have tried clicking on on the task bar, but none of the options in that link result in any information.

Is this a problem with Thunderbird or with my computer? And in either case, how do I solve it?

My computer is HP Pavilion a1550y and I use Windows XP Home.

 

Email identification solved.

 

So, How did you solve it. I might learn something.

Ray

 

I think all you will learn is how to embarrass oneself. I mistook the small box in the upper right hand corner which has a brief drop-down menu including "sender" for the very small box at the top of the scroll bar. When I tried that, of course it opened and I clicked "sender" and all was well. How it got off track in the first place I don't know, but there it is...