ProtonMail can be used to send encrypted email messages with an expiration limit. This can be great in communicating time sensitive information which needs to have a very limited access to select recipients.
These messages can be delivered to any email domain and doesn’t require a ProtonMail sign-up to read them.
Here is how:
Login to ProtonMail and click on COMPOSE button.
At the bottom, click on the lock icon for setting the message encryption.
Next, set a password. This also needs to be known to intended recipients so that the message can be decrypted. Use a password hint if needed and click SET to encrypt the message.
By default, encrypted messages to non ProtonMail users are set to expire after 28 days. The clock icon at the bottom of message composing window can change this.
Again, click SET to set the expiration time if needed.
Send the message once the password is set along with expiration time.
At the recipient end, the received message won’t be decrypted yet. To do this, click on View Secure Message.
Enter the same password that was set before and click DECRYPT.
Once decrypted, the message will now be visible along with a countdown to expiration.
All done.