Open-source email security tools

3 email security tools whose code is public under an OSI-approved license, rated for privacy with evidence. Picks first, then by score.

1. DKIM Verifier Grade B

   Thunderbird add-on that verifies DKIM signatures and shows the result in the message header, to help spot spoofed email.

   MIT. Source code

2. Email Privacy Tester Grade B

   Tests whether your mail client "reads" emails before you open them, and what analytics, read-receipts or other tracking data it leaks back to the sender.

   GPL-3.0. Source code

3. Paperweight Grade B

   Local-first desktop app that scans an inbox to list the services holding your data, then helps unsubscribe and send data deletion requests.

   MIT. Source code

Compare all 3 email security tools, open source or not.