ProtonMail offers free end-to-end encrypted email service through a convenient web interface and mobile apps. That said, exporting emails or accessing them by any other means is a challenge, and the free version of ProtonMail could offer more productivity features.

Information in this article applies to the web version of ProtonMail as well as the ProtonMail apps for iOS and Android.

ProtonMail Pros and Cons

Compared to similar services, ProtonMail provides several benefits and a few limitations.

What We Like

  • Easy and secure email encryption.
  • Multiple encryption options.
  • Set emails to expire after a certain date.
  • Access ProtonMail on any device with the mobile app.

What We Don’t Like

  • Occasionally sluggish web interface.
  • Limited search and organization features.
  • Cumbersome integration with other email clients.

Free vs. Premium ProtonMail

Anyone can sign up for ProtonMail and get 500 MB of online storage for free. Paid accounts include up to 20 GB of storage in addition to priority customer support and other productivity features. The free service should suffice if you only occasionally send encrypted email.

What Is End-to-End Encryption?

Encryption protects the content of emails from prying eyes. As messages you send make their way from your computer to the recipients’ inboxes, they can be intercepted by malicious third parties along the way.

With end-to-end encryption, the message is encrypted as soon as you send it, and it’s only decrypted when the recipient opens it. Because the message can be unlocked only with the recipient’s own personal key, nobody in between can decrypt it. Thus, services like ProtonMail make it possible to transmit sensitive information without worrying about it falling into the wrong hands.

How ProtonMail Encrypts Email Messages

When you exchange emails with another ProtonMail user, the messages are automatically encrypted with their key in your browser or smartphone app, and they are deciphered only when the recipient opens them. Therefore, you don’t have to worry about setting up passwords.

When you send a message to someone who does not use ProtonMail, you get the option to encrypt it with a password. The recipient will receive a message containing a link to the ProtonMail web interface, and they must enter the password to view your message. From that same interface, they can reply with an encrypted message protected by the same password.

You can also use PGP to encrypt your messages the traditional way, and you can export both your public and private PGP keys from ProtonMail for use with a different service. Conversely, if you’ve already been using encrypted email, you can import your existing keys into your ProtonMail account.

The ProtonMail Interface

The ProtonMail web interface includes all the folders you would expect (such as Archive and Spam). There are also color-coded labels and stars to make messages stand out. You can even make rules to automatically label incoming mail. Paid ProtonMail users can create as many custom rules as they please while free accounts are limited to one custom rule. It also has a simple auto-response feature for when you’re going to be away.

ProtonMail has a simple auto-response feature for when you're going to be away.

Don’t like typing out “@protonmail.com” every time you enter your address? Select pm.me on the ProtonMail interface to reduce it down to a simple “@pm.me.”

Sending Messages With ProtonMail

ProtonMail’s rich-text editor allows you to customize your message with HTML formatting and inline images. Although ProtonMail supports a few keyboard shortcuts, it offers limited help with composing messages. For example, you cannot set up templates or text snippets, and ProtonMail does not suggest text, times, or recipients.

That said, ProtonMail’s cryptography brings another benefit: You can set emails to self-destruct at a time you specify. For additional security, you can enable two-factor authentication.

For additional security, ProtonMail offers two-factor authentication.

Searching for Messages in ProtonMail

ProtonMail has a search feature, but the fields you can search for are restricted to information in the message headers such as senders, subjects, and dates. Encryption prevents ProtonMail from searching the bodies of messages, but if you set up the ProtonMail Bridge application on your desktop, you can expand your searches to include the contents of emails.

How to Use ProtonMail With Your Other Email Accounts

ProtonMail Bridge is a desktop application that lets you link your other email accounts with your ProtonMail account. Because of the way ProtonMail encrypts mail, it cannot connect directly with other email clients, so the Bridge acts as a remote server to facilitate communication. Any mail client that supports connecting to a remote mail server, such as Outlook and Thunderbird, can connect to ProtonMail this way.

Unfortunately, ProtonMail cannot collect mail from your existing email accounts, and you cannot set it up to send mail using any of your existing email addresses either. Nonetheless, using your favorite email program with ProtonMail might help with some of the productivity shortcomings.

ProtonMail Bridge

ProtonMail Bridge is only available for paid subscribers.