How come every picture from every e-mail I get?

They wind up there because sometime in the past that was the defaulted viewer. To delete them, you can go through My Computer, find them in the file list, select and delete. To do many at once, highlight the first, hold the shift key and click on the end one. All will highlight and you can select delete. Using contol key and clicking will select the ones picked. then you can delete only those.