Witnessed for Gmail

Auto-BCC seal@witnessed.cc on every Gmail compose, and look up any sender's proof-of-business record at a click.

Witnessed is a public, verifiable record of every business email your domain sends. This extension brings the two things you need inside Gmail — without OAuth, without leaving your browser. ━━━ What it does ━━━ • Auto-seal outgoing mail. Every new Gmail compose gets seal@witnessed.cc silently added to Bcc. Your outbound business email builds a public, cryptographically-verifiable history that can't be backdated. Remove the address on any individual message if you ever need to — the extension won't re-inject on a thread you've already touched. • Verify any sender with one click. Open the toolbar popup on any Gmail tab. It shows a proof-of-business chip for every sender domain you can currently see — whether you're in a thread with multiple participants or scanning an inbox. Each row deep-links to the full public page at witnessed.cc/b/<domain>. ━━━ How it connects to Witnessed ━━━ Witnessed is provider-agnostic. This extension is the easiest way in if you use personal Gmail on Chrome. Admins running Google Workspace or Microsoft 365 can set up the same behavior at the server level — see https://witnessed.cc/setup. People on Proton, Fastmail, or Apple Mail can simply paste seal@witnessed.cc into Bcc on any business email. All three paths grow the same public record. ━━━ Privacy ━━━ The extension is fully local. No OAuth. No server-side mail access. No analytics. No tracking. The only network request the popup ever makes is a GET to witnessed.cc's public JSON endpoint for a single domain lookup, and even that is cached locally for up to 24 hours per domain. Full privacy policy: https://witnessed.cc/privacy