emailrules.today
Stop 8 of 8DeepThe next morning

Seed test / seed list

Sending to a panel of test inboxes to guess placement — scores vary wildly between tools.

Say it out loud

“Sending to a panel of test inboxes to guess where mail lands. Two tools will give two different answers.”

A seed test drops your campaign into a panel of provider inboxes and reports where it landed. The panels are small, they are not your recipients, and they have no engagement history — which is most of what placement is actually decided by. Two vendors routinely disagree about the same send.

The arithmeticThe same campaign, two vendors, same hourExample numbersscrolls →
Vendor A Gmail inbox 94%
Vendor B Gmail inbox 71%

Same send, same hour. Different panels, different histories, different answers.

A seed address has no purchase history with you,
no opens, no replies, no folder moves.

Which is most of what Gmail actually uses to decide. The panel cannot model the thing it claims to measure.

Useful as one signal among several, especially before a large send. Never as a number to report as truth.

Nobody's

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

What goes wrong

Reporting a seed score to a client as a placement percentage. It is a measurement of a panel, and when the next vendor's panel disagrees you have to explain both numbers.

What people get told

The claim. “A seed test tells you your inbox placement.”

Actually. It tells you the placement of that panel's addresses. Real placement varies by recipient, by engagement history and by segment, which is exactly the variation a fixed panel cannot contain.

See also

Where this sits

Stop 8, it comes back as numbers. The reactions become a dashboard, and the dashboard is lying to you a little.

← Beforerua (DMARC reports)

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.