If you use Gmail, you already enjoy pretty decent protection. It's offered HTTPS protection since launch, and that's been the default option for the last four years. Now it's the only option, and that's good news for everyone. From Google:
Starting today, Gmail will always use an encrypted HTTPS connection when you check or send email. Gmail has supported HTTPS since the day it launched, and in 2010 we made HTTPS the default. Today's change means that no one can listen in on your messages as they go back and forth between you and Gmail’s servers—no matter if you're using public WiFi or logging in from your computer, phone or tablet. In addition, every single email message you send or receive—100 percent of them—is encrypted while moving internally. This ensures that your messages are safe not only when they move between you and Gmail's servers, but also as they move between Google's data centers—something we made a top priority after last summer’s revelations.
All that means is that every email you send is protected by Google's strong encryption at every stage of its journey. It's safer and more secure than ever. That doesn't mean you can go around clicking shady links or using simple passwords. The weakest link in any defense is a careless user. Click here to learn all about Gmail's new security standards.