Klar vs Anti-Spam SMTP Proxy Server
What actually differs: where each filter runs, who gets to read your mail, and what it costs.
| Aspect | Klar | Anti-Spam SMTP Proxy Server |
|---|---|---|
| Runs on | Your Mac | Your mail-server infrastructure |
| Who can read your mail | No one new during filtering. Classification stays on your device. | No new third party. The proxy inspects mail on the server where you deploy it. |
| Works with | Apple Mail, with any account: IMAP, Gmail, iCloud, Exchange | In front of an SMTP server on Linux, Windows, macOS and BSD |
| Price | Free forever | Free and open source |
Klar fits better when you want a personal Apple Mail filter, not a Perl-based server proxy to deploy and administer
The honest picks
- Anti-Spam SMTP Proxy Server
- ASSP combines Bayesian and Hidden Markov filters with greylisting, DNS lists and SPF. It also controls attachments and connects to antivirus tools. Pick it when you want that depth and are ready to run a configurable SMTP proxy. For a lightweight self-hosted layer, 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: sourceforge.net. 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.
