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.
Deliverability testing for newsletter senders
Will your newsletter actually land
in the inbox?
Forward your newsletter to the test address below. In about 30 seconds you get a deliverability score, where it lands — Primary, Promotions or Spam — and the three things to fix. Built for senders on Mailchimp, Substack and Beehiiv.
Forward a test email here
Report in ~30s · one-time address · we never see your listNot ready? See a sample report first.
Example resultmailtester.ai/report/live
Deliverability62/ 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
Built in the EU · GDPR by default
7,000+ emails tested
AI placement forecast for Gmail, Outlook, and Yahoo inboxes.
Free · €0for unlimited scoring. €9.99 for AI deep-dives.
02~10 sec
We read it.
We check the subject line, content, links and authentication, the signals Gmail, Outlook and Yahoo filters weigh. Then we forecast where your email lands in each one: Primary, Promotions, or Spam, with a confidence level.
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.
See it work
Forward an email, watch the score climb
One envelope, eight seconds: a 62 you can fix into a 91. Forward your send and the report builds itself — verdict, inbox placement, and three plain-English fixes. It's free email testing for any newsletter or EDM you can send a test of.
Want just the tab call? The free email inbox tester predicts Primary, Promotions or Spam for a single send.
Wait — which one are you looking for?
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
That's us
Inbox placement
Will Gmail actually show it?
You forward one email (newsletter, launch, client note) to a one-time mailbox. We check it, forecast which tab it will land in at Gmail, Outlook, and Yahoo, and tell you 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
Use both, actually — verify the list, then score the send.Address-validity tools: ZeroBounce, NeverBounce, MXToolbox
Why we built it
We check whether your sends will land. That's the whole product.
Forward from any of these.
We score the same way.
+ Gmail, Outlook, anything with "send a test"
You're here
Beehiiv
Creator newsletters
Forward a test
Kit
Creators in their element
Forward a test
Substack
Indie writers
Forward a test
Mailchimp
Weekly newsletters
Forward a test
Klaviyo
Shopify DTC
Forward a test
Brevo
Small ecommerce
Forward a test
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
Credits
5 AI deep-dives. Top up only when you need them — credits never expire.
€5one-time · 500 credits
Starter
1,100 credits a month, about 11 AI deep-dives. Cancel anytime.
€9.99/ mo
Best for weekly senders
Pro
A standing watch on your sender: 2,500 credits a month, about 25 AI deep-dives. Re-check every weekly send.
€19/ mo
Send your next one to the inbox.
Takes less time than picking a hero photo. Free, and no card at any point.
Or send me a sample report first.
GDPR by defaultEU-hosted · BratislavaISO 27001soon
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