emailrules.today
Stop 4 of 8WorkingUnder one second

Email headers

Hidden technical lines on a received message — authentication results, path, unsubscribe headers live here.

Say it out loud

“The hidden technical record at the top of a message. It is the only place that shows what actually happened.”

Headers are the metadata carried at the top of a raw email: Received, Authentication-Results, DKIM-Signature, List-Unsubscribe and dozens more. DNS shows what you published; headers show what you actually sent and what the receiver made of it. That is a different question, and it is usually the one you need answered.

On screenGetting them out of a real inboxPublished valuesscrolls →
Gmail open the message → ⋮ → Show original → Copy to clipboard
Outlook File → Properties → Internet headers
Apple Mail View → Message → All Headers (⌥⌘U)
Do not forward the email to yourself instead.

Forwarding rewrites the Return-Path and re-stamps the Received chain — it destroys exactly the evidence you were trying to collect.

Nobody's

Nothing to action — it changes a number or a risk you report.

What goes wrong

Forwarding the message rather than copying the original. The forward carries your own authentication results, not the sender's, and every conclusion drawn from it is about the wrong message.

Check it yourself

Paste them and get a plain reading of what happened

Run it now →

See also

Where this sits

Stop 4, identity gets checked. The receiver works out whether the message really comes from who it says it does.

← BeforeDMARCNext →BIMI

FAQ

Awkward questions

Who is this actually for?

People who ship email and are too busy to re-read every PDF: week-one marketers, lifecycle/CRM, deliverability, multi-country ops, DTC brands, agencies — on Klaviyo, Mailchimp, Braze, HubSpot, SFMC, or something else. Pick your tool and geos so product-specific pages only appear when they match. EU and UK are first-class filters. Not for people who sell tools about email and need a fake score to demo.

Why only ~40 rules? Isn’t that… thin?

On purpose. A wall of 400 undated “best practices” is how you look busy and still get burned. Every page needs a primary source we actually read. Thin and checkable beats fat and folklore. Europe, bulk inbox rules, measurement honesty, and protocol topics like BIMI/DMARC policy are on the shelf when we can cite them — not every Member State and not every vendor myth. Coverage map lists what we still refuse to invent.

Is this legal advice?

No. If it were, you’d have a billable hour and a longer PDF. This is a dated operator reference written by an email geek. Confirm anything high-stakes with counsel who knows your facts. Same for “will this make me compliant?” — no tool does that. Lawyers and judges do. We say what the sources say and what to do first on Monday.

Why no trust score out of 100?

Because we refuse to invent a number you can’t audit. Fake scores sell seed tests and panic. You get findings, dates, and links. If that feels less exciting than a red dial, good — you’re not the red-dial customer.

Why should I trust you more than my ESP’s blog?

ESPs sell seats. Seed-score vendors sell fear. AI invents citations when nobody watches. We sell nothing today — no pixels, no placement scores, no affiliate — so we can say when a tool is the problem. A human verifies, dates, and corrects in public. Tools may help draft; they do not ship unsourced claims. Check the primary links. Fail that test and leave.

Do I need an account?

No. Filters live in this browser and the URL. Share the link. That’s it. Accounts come later only if they earn it — not so we can nurture you about email.

I’m an agency. Where’s multi-client mode?

We tried a client-name CRM on the setup card. It made the product feel like work before it felt useful. Role filters + copy link + one-page brief (optional PDF title) is enough for now. Complexity comes back when the free shelf is habit, not before.

Is the quiet changelog a bug?

No. Quiet means nothing material moved. We don’t invent urgency so the homepage looks “alive.” Sticky risks still show what usually needs a person when the market is still.