Private.Ki Mail vs Proton Mail

Private.Ki Mail is an email service that encrypts messages between Private.Ki users. Message bodies, subjects, and attachments are encrypted on the sender’s device and decrypted on the recipient’s device, with encryption and signature checks shown for each message. Mail to outside providers uses end-to-end encryption when the recipient has a PGP key; otherwise it is delivered normally and marked accordingly. The Free plan costs nothing and includes one @private.ki address, encrypted email and messenger, signatures, recipient autocomplete, search, and attachments up to 25 MB per file. Undo send supports 5, 10, 20, or 30 seconds, and standard mailbox folders are included. Web, iOS, and Android access are listed. Security features include TOTP two-factor authentication, QR pairing, and device-bound sessions. The maker says it cannot recover a lost passphrase or protected key and has no independent audit yet.

Proton Mail is an encrypted email service available on the web, Windows, macOS, Linux, iOS, and Android. Its free plan lists 1 GB of storage and one email address, although its FAQ says storage starts at 500 MB; the free tier is described as having the same security level as paid plans. The service uses end-to-end and zero-access encryption, with open-source apps and independent audits. It blocks email trackers and includes phishing and spam protection, password-protected messages, and link confirmation. Users can schedule, undo, or snooze emails and organize messages with folders, labels, and categories. Easy Switch imports email, calendars, and contacts from other providers. Paid plans support external email clients through IMAP and SMTP using Proton Mail Bridge. Mail Plus lists 15 GB of storage, 10 extra email addresses, and one custom domain. Paid subscriptions include a 30-day money-back guarantee, and the desktop app has a 14-day free trial. Paid plans display monthly billing; the listed starting price is 3.99 /user/mo.