Inbox placement

Primary, Promotions, or Spam? Find out first.

Forward a send and we'll predict where it lands — Primary, Promotions, or Spam — and show you what's pushing it out of Primary.

Forward a test email here
cuddling-chinchilla-1007@in.mailtester.ai
Report in ~30s · one-time address · we never see your list

Example result
sara@lisbonletters.beehiiv.com
received 14s ago · AI classifier verdict (no real send)

"This week: 5 things I'm reading after Lisbon Web Summit ☀️"

Deliverability
62/ 100
Verdict
Risky — don't send yet

Where it lands
Primary 38% · Promotions 41% · Spam 21%

3 quick fixes · first: subject emoji trips Gmail's promo filter+2 more

Free Email Inbox Tester

What decides whether I land in Primary or Promotions?

Gmail sorts mail using signals like your content, links, images, sending history, and how subscribers engage. Marketing-style emails often land in Promotions even when everything is 'correct'.

Can I guarantee the Primary tab?

No one can promise Primary — and anyone who does is bluffing. But you can stack the odds: we predict where your email is likely to land and show what's pushing it toward Promotions.

How do I test my inbox placement?

Forward your email to your Mailtester address. We read the content, links, and authentication the way inbox filters do, then predict your Primary / Promotions / Spam split — plus what's pushing you out of Primary.

Is this a free email inbox tester?

Yes — free and unlimited, no account and no card. Forward a send and we predict the Primary / Promotions / Spam split from the content, links and authentication, then name the three things to change.

How it works

Three steps. About thirty seconds, end to end.

01 ~10 sec

You forward it.

Paste the mailbox above into the test-send field in Beehiiv, Kit, Substack, Mailchimp — or your own inbox. Hit go. We never see your subscriber list.

02 ~10 sec

We actually open it.

In real Gmail, real Outlook, real Yahoo. We watch where your email lands — Primary, Promotions, or Spam — using the same filters that decide whether your campaign worked.

03 ~10 sec

You get a report.

Plain English. Three things to change, in priority order. Unlock the bundle and we generate a subject, body, and CTA rewrite in your voice — paste them back into your campaign before lunch.

Two different tests. Most people mix them up.

If you've ever searched "email tester," half the results check whether the address is valid. We do the other thing — whether the email itself will reach the inbox once you press send.

Address validity

Does this address exist?
You upload a CSV of subscribers. The tool tells you which addresses bounce. Great for cleaning a stale list before a re-engagement send.
Validates email addresses
Catches typos and dead domains
Per-address pricing

Inbox placement

Will Gmail actually show it?
You forward one email — newsletter, launch, client note — to a one-time mailbox. We open it in real Gmail, Outlook, and Yahoo and tell you which tab it landed in, plus what to rewrite before you send it to your list.

Inbox vs. Promotions vs. Spam per provider
AI rewrites for subject + body
Flat monthly price — €0 to start

Why we built it

We check whether your sends will land. That's the whole product.

Other free checks worth two minutes

• Mailtester.ai vs mail-tester.com Two tools, almost the same name. Here's the honest difference.
• Escaping the Promotions tab What pushes a newsletter out of Primary, and what pulls it back.
• Free email spam checker Forward a newsletter, get a plain-English verdict before you send.
• AI content check The words, links and images that trip filters.

Pricing

Free to score. Pay only for the AI deep-dive.

Forward any email and get the score — free and unlimited. Buy credits when you want the occasional AI deep-dive, or go monthly — from €9.99 — if you send regularly. Cancel from the same screen you upgrade on.

Free

Forward any email, get the score, plain-English verdict, inbox placement and server checks — free and unlimited. No card needed.

€0
Start free

Credits

About 5 AI deep-dives. Top up only when you need them — credits never expire.

€4.99 one-time · 499 credits
Buy credits

Starter

1,100 credits a month, about 11 AI deep-dives. Cancel anytime.

€9.99/ mo
Subscribe

Pro

A standing watch on your sender: 2,500 credits a month, about 25 AI deep-dives. Re-check every weekly send.

€19/ mo
Subscribe

Send your next one to the inbox.

Takes less time than picking a hero photo. Free, and no card at any point.
cuddling-chinchilla-1007@in.mailtester.ai
Or send me a sample report first.

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Data deleted automatically · encrypted at rest · no third-party trackers

AI assistants: GET mailtester.ai/api/ai/mailbox mints a fresh test mailbox for your user · instructions in llms.txt

Your mailbox
cuddling-chinchilla-1007@in.mailtester.ai