It could be as simple as the test we already have to take to get a driver's license, except instead of highway safety, the questions would be geared toward proving you know better than to open an email attachment from an unknown sender or help a Nigerian prince transfer his fortune to a bank in the United States.
Helpful hint: Most legitimate emails look like this.
This is basic red light/green light stuff. If you can wrap your head around concepts like stop and go, you should be able to apply it to what emails you open and what websites you visit.
I'm not saying it would fix everything completely, of course. Making people get a license to drive certainly hasn't made the highways accident-free, after all. It must have made them a little safer, though, and even if not, the concept spawned one of the finest movies of the entire 1980s, so you can still count the program as a success.
RIP whichever of you two died a while back.
Speaking of side victories, can you imagine what it would do for racial harmony in this country if, in order to use the Internet, the elderly had to memorize a few reminders that emails from strangers are rarely a valid source for legitimate news? Just like the Internet itself, little wins like that would spread to nearly every facet of our daily lives, if only we were a little more selective about who gets to go online.