ProtonMail 101: How to Send End-to-End Encrypted Emails to Non-ProtonMail Recipients by smartphones.gadgethacks.com
It can be hard to get all of your friends, family, coworkers, and acquaintances to jump on board with the more-secure email system ProtonMail, but that doesn't mean you can't still send them encrypted emails. Best of all, they won't even have to install any other apps or extensions to read or reply to the messages.
ProtonMail 101: How to Send Self-Destructing Emails by smartphones.gadgethacks.com
When you're sending sensitive information via email, it's best to do so with end-to-end encryption. Even better, set the email to destroy itself after a set amount of time for a little piece of mind.