You could also save it to your computer and try to open it with various programs you do have i.e. wordpad/notepad/textedit (to do this right click, or control + left click on the icon, choose "open with", browse to whatever program you think might work. Sometimes this works. Probably you'll just get a bunch of gibberish. The best thing you can do is download whatever program created the file and run it with that. Too find out what program you need to open the attachemnt look at what ends the file name and try to find out based on that. For instance if it ends in .pdf you need adobe acrobat reader or a similar program, if it ends in .zip you need a program that opens archive/zip files. Too find some of these programs you can check out a site called oldversion.com.