Sign it with the Trust Identity Protocol (TIP) by The AI Lab. With the free TIP browser extension and a TIP-ID, you press Sign with TIP next to Send. Your device signs the email after a fresh face or fingerprint check, and a Verify link goes under your message. Anyone who received it can open the link, see your verified name, and check that the email is exactly what you signed and was sent to them.
It is a way for a verified person to sign an email so the people who receive it can check who signed it, that it was sent to them, and that nothing was changed. The sender holds a TIP-ID, issued once after an ID and live face check by an accredited Verification Provider. Each email is signed on the sender's own device with ML-DSA-65, the post-quantum signature standard NIST published as FIPS 204, and recorded on the TIP network. A signed email is a Verifiable Asset with its own CTID.
SourcesNIST, FIPS 204
They need nothing but the link. Opening the Verify link shows the record, with who signed it, when, and how the sender says it was made. Verify content on that page checks the subject, message, From address, To and Cc list and attachments against what was signed, on the reader's own device, without uploading anything. Recipients who install the free TIP extension see "Signed by" and the sender's verified name directly in Gmail and the other supported webmail.
No. The public record holds a fingerprint of the email, never its words. Its subject, message and addresses are never published. In TIP 2.9.74 and later, the subject and message never leave your device at all. Who it was sent to and who sent it are sealed into the record, so only someone who already has the email can check them. Bcc recipients are sealed privately, so only the sender can show who was copied. Emails are never scanned by the TIP Classifier.
They can paste it, but it will not pass. The record holds a fingerprint of the original subject and message, so a different email fails Verify content, and the TIP extension reports it as changed. The link only ever proves the email it was created for.
The recipient check fails. The record seals the list of people the email was signed for. When the same email is re-sent to a new address, its To and Cc no longer match that sealed list, so Verify content does not confirm it. A genuine signed message cannot quietly be reused against a different victim.
No. A stolen email password gives access to your mailbox, not to your TIP key. Your key stays on your own device, and every signature needs a fresh face or fingerprint check there. There is no unlock window and no saved session that skips it. An email the hacker sends from your account will carry no valid signature, which is exactly what your contacts should look for.
No. Keep all of them. They protect domains and filter mail at scale, and TIP does not block or filter anything. TIP adds what they cannot, a check that a verified person signed this exact email for these recipients. That covers the lookalike domains, fake display names and hacked mailboxes that pass domain authentication.
Signing works in Gmail, Outlook, Yahoo Mail, AOL Mail, iCloud Mail, Proton Mail, Zoho Mail and Fastmail, through the free TIP browser extension for Chrome, Firefox, Safari, Arc and Brave. You can also write and sign an email in the extension's Email form and send it from your usual mail. Checking a signed email works in any browser on any device, through its Verify link.
Make it a rule people can follow. Executives, finance staff, title companies and law firms sign every payment instruction and every change of bank details with TIP, and tell customers and vendors to treat any unsigned one as unconfirmed and call. Keep callback checks and dual approval for large transfers. The signature does not replace those controls. It gives them a check that a lookalike domain or a hacked mailbox cannot pass.
Checking a signed email is free for everyone, with no account. Signing is free for individuals, nonprofits, schools and universities, government bodies, journalism organizations for editorial use and businesses under USD 100,000 in annual revenue. Larger businesses use a published commercial license, with every tier listed at theailab.org/tip-license.
