Aster Mail vs Private.Ki Mail
Aster Mail
astermail.orgPrivate.Ki Mail
private.kiSide by side
| Figure | Aster Mail | Private.Ki Mail |
|---|---|---|
| Price from | $2.42/mo | $0.42/mo |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | Yes | — |
| Web | Yes | Yes |
| Windows | Yes | — |
| macOS | Yes | — |
| Linux | Yes | — |
| iOS | Yes | Yes |
| Android | Yes | Yes |
| Plans published | 4 | 6 |
| Spec score · Secure Email Providers | 9.5 (#1) | 8.1 (#18) |
| Spec score · Email providers | 9.4 (#2) | 8.0 (#17) |
| Email encryption | Mail between Aster accounts is end-to-end encrypted automatically. | Mail bodies, subjects and attachments between Private.Ki users are encrypted on the sender’s device before transmission and decrypted on the recipient’s device. |
| End-to-end encryption | Yes | Yes |
| Free plan | Yes | Yes |
Plans
Private.Ki Mail
- FreeFree
- Plus$5 a month
- Plus$5 a year
- DedicatedPriced on request
- FreePrice not published
- TeamsPriced on request
In their own words
Aster Mail
Aster Mail is an open-source email service with a free plan and paid tiers. It supports web, desktop, and Android, with an iOS beta on TestFlight; native desktop apps are available for Windows, Mac, and Linux. Aster Bridge lets desktop mail apps connect over IMAP and SMTP. Mail between Aster accounts is automatically end-to-end encrypted and uses hybrid post-quantum encryption. The free plan costs nothing and includes 10 GB of encrypted storage, five aliases, one custom domain, two mail rules, attachments up to 25 MB per message, and Bridge access; no trial or credit card is required. Aster says its email is hosted in Germany under EU privacy law and that it does not use ads, inbox scanning, or AI on the inbox. QuickSwitch imports mail from Gmail, Outlook, Yahoo, Proton, and other IMAP providers. MBOX mailbox export is free on every plan. Paid plans start at $2.42 a month, billed annually, with the final amount determined at checkout. Aster Mail was founded in 2026 and is headquartered in Orlando, Florida, United States.
Private.Ki 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.