ProtonMail earns bonus points for encrypting subject lines and recipient/sender email addresses, but they are not end-to-end encrypted. It uses PGP/MIME, which encrypts both the email's body and its attachments to prevent even the type or name of the attachment from being leaked to a third party. PGP encryption is built-in in ProtonMail, and encryption and decryption are fully automated. In contrast to Mailfence, you cannot send password-protected emails to other users of ProtonMail. ProtonMail has switched from RSA to Elliptic Curve Cryptography (ECC), a more secure algorithm to store your keys.

Similar to Mailfence, it uses digital signatures and encrypts public and private keys to protect email messages. ProtonMail also offers end-to-end encryption using the TLS 1.2 and OpenPGP and AES 256-bit protocols to secure your messages while they are in transit and at rest, respectively. The only issue with Mailfence is that subject headers aren't encrypted either in transit or at rest. Mailfence makes it easy to use keys by handling all of this OpenPGP key generation and management inside your account. Mailfence creates a 4096-bit-long RSA private key, which is then encrypted using the passphrase you've chosen and stored on the servers. This is because the private key, which is secured by a passphrase that you choose, can decrypt all of your data. People who receive encrypted messages can access the public key, but nobody-not even Mailfence-has access to the private key. It uses OpenPGP digital signatures or key pairs to secure your data. You can even send password-protected emails to both Mailfence users and non-Mailfence users for additional security. Mailfence uses SSL (Secure Sockets Layer) and TLS (Transport Layer Security) encryption to secure your email messages and attachments in transit, and OpenPGP is used to encrypt messages at rest. The encrypted messages are only accessible by the recipient any other third-party will only see indecipherable texts. Mailfence offers end-to-end encryption to all users, which means that your emails are protected from the time you press 'Send' until they get to their intended recipient.

Proton mail