Share links & proof of delivery

Because Mailway archives every message byte-for-byte, it can do something providers can’t: show a third party exactly what left, and prove it. Two features build on that archive — support teams use the first daily; legal, finance, and compliance teams reach for the second.

Share links

Any archived mail can be shared as a link on mailway.to — no Mailway account needed to view it:

https://mailway.to/m/<token>

• Expiring by design — you pick 1 hour up to 4 days; the default is 1 hour. Links can be revoked early, and every mint/revoke is audited.
• Optionally password-protected — set an access password at mint time for anything sensitive.
• Complete — the viewer shows the rendered mail plus its text part, headers, attachments, and the verbatim raw source, with the message’s own SHA-256 fingerprint. What the recipient’s mail server got is what the viewer shows.
• Safe — the mail renders in a sandbox on a separate cookie-less domain; customer HTML can’t run scripts, and share pages are no-referrer + noindex.

Use it for “can you check what my customer received?” — instead of screenshots and forwarded forwards, send the actual artifact.

Proof-of-delivery certificates

A share link shows a mail; a certificate proves it. For any archived mail, Mailway can issue a tamper-evident certificate binding together:

1. the message content (SHA-256 of the exact bytes),
2. the provider handoff (which provider accepted it, when),
3. confirmed delivery, where delivery events exist (provider-attested),
4. Mailway’s own Ed25519 signature over the evidence,
5. an RFC 3161 timestamp from an independent time authority, countersigning that signature — the certificate provably existed when it says it was issued, and can’t be back-dated. Not even by Mailway.

Certificates verify offline — a relying party doesn’t have to trust Mailway’s servers, or even reach them. A certificate attached to a share link is checked right in the reader’s browser, and the downloaded .json carries everything — evidence, signature, public key, timestamp token — so it keeps verifying forever with a dependency-free one-liner (shown next to the certificate) plus standard openssl ts for the timestamp, even in an air-gapped environment.

Honest claim levels

A certificate states exactly what it can prove: accepted (provider handoff) or delivered (event-confirmed receipt). It never inflates one into the other. And where Mailway itself re-encoded the message (the opt-in for structured-only API providers), no certificate is issued at all — byte equality wasn’t preserved, so it isn’t certified. Plain share links remain available.

Availability

Share links are available on Pro plans and up; certificates on Business and up. Minting either is role-gated and written to the team’s audit log. Both live and die with the mail’s retention window — a link is revoked when the content it exposes is removed, while an already-issued certificate keeps verifying offline forever.