You can have a virus sent to you through e-mail, it would be in an infected file. So the rule of thumb here is that you don't open files sent as an attachment from people you don't know, but don't worry about the actual e-mail itself. Understanding viruses is all well and good, but what is really important is knowing how to prevent or destroy them, even when you don't know they are there. This takes software. I am reviewing Norton AntiVirus for Macintosh 5.0.
Updates are free for registered copies the first year after purchase.
Updates are important because as new viruses are created, new techniques are necessary to destroy them. This software is very easy to use and anyone who can operate their computer at the basic level can use it. I had to try it out on a friend's computer because mine is a Mac 68030. I have System 7.6.1, but it is not a Power Macintosh. You probably want to make sure your machine will handle the program before you spend the money.