Mail opens and automatically opens ALL emails!

[sungrrl]

My 85yr old mum has a macbook pro and I am trying to assist her as she has a crazy problem whereby when Mail is opened...ALL emails ever recieved open in quick succession until all 500 are sitting open in a pile on the screen!
It may be she has inadvertedly changed a setting, but I can't work out what it is!
Any help gratefully received!

 

[ScoobyMcDoo]

Is she running Lion? If so, maybe she once accidentally opened all of her messages with something like cmd-a, cmd-o. Then maybe Lion's "feature" to open the app back up just as she left it, is causing it to happen over and over.

If you think this might be the case, try doing a option-command-w to close all windows, exit mail, then start mail to see if the problem is fixed.