A private alternative to SpamAssassin
Klar filters spam on your Mac, inside Apple Mail. No account, no cloud, nothing to hand over.
If you are weighing up SpamAssassin, here is how Klar differs and where each one is the better pick.
| Aspect | Klar | SpamAssassin |
|---|---|---|
| Runs on | Your Mac | Your mail server |
| Who can read your mail | No one new during filtering. Classification stays on your device. | Runs on your own server. Mail stays on your infrastructure. |
| Works with | Apple Mail, with any account: IMAP, Gmail, iCloud, Exchange | Server-side, in front of any mailbox (Postfix, Sendmail and other MTAs) |
| Price | Free forever | Free and open source |
Klar fits better when You read mail in Apple Mail and don't run your own mail server
The honest picks
- SpamAssassin
- The classic open-source filter: rules plus Bayesian scoring, two decades of deployment. Powerful once tuned, but it lives on a mail server you run and maintain, not on your Mac. Or run Klar on your own server instead: the same filter is an open-source milter for Postfix and Stalwart, one command to install. See Klar Pro.
- Klar
- Pick Klar if you read mail in Apple Mail and want a modern multilingual model that runs entirely on your Mac. No account, no cloud, nothing to hand over.
Product and price details from the vendors' public pages, July and August 2026: spamassassin.apache.org. Klar is not affiliated with any vendor named here. No vendor endorses Klar. Product names only identify the tools.
Reclaim your inbox
Spam filter for Apple Mail. Free on the App Store.
