What are spam trigger words?

Phrases that appear far more often in spam than in legitimate mail, which filters learned to associate with it — things like 'no credit check', 'make money fast' or 'dear friend'. Rule-based scanners such as SpamAssassin still carry explicit rules for some of them, so the effect is real.

Will removing spam words fix my deliverability?

Usually not on its own. Word choice is a small input compared with authentication, sender reputation and how your recipients engage. If your emails are going to spam and your copy is already clean, the cause is almost always somewhere else.

Is this spam words checker free?

Yes, and there is no signup. Your copy is checked in your browser and is never uploaded, stored or sent anywhere.

Does the word 'free' send emails to spam?

No. 'Free' is ordinary marketing vocabulary and appears in enormous volumes of legitimate mail. Density is what matters — 'free' once in a real sentence is fine; six hard-sell phrases stacked together is a different signal.

How do I check where my email actually lands?

Forward a real send to a Mailtester address. In about 30 seconds you get a deliverability score, your SPF, DKIM and DMARC results, a placement forecast and the three fixes most worth making.

Free spam words checker

Which words in your copy are working against you?

Paste your subject line or the whole email. We'll flag the trigger words as you type — and tell you honestly how much they actually matter.

Stays in your browser

Your copy is checked on this device and never uploaded. No account, no send, no storage. Close the tab and it's gone.

Paste your subject line or email copy

No words yet

The honest version

What spam trigger words actually do

What a “spam trigger word” really is

Spam filters were trained on decades of real spam, so certain phrasing genuinely does correlate with it — “no credit check”, “make money fast”, “dear friend”. Rule-based scanners like SpamAssassin, which runs as part of a full Mailtester check, still carry explicit rules keyed to phrases like these. The effect is real. It is just far smaller than the internet implies.

Why word lists matter less than they used to

Filters stopped relying on vocabulary years ago, because senders adapted faster than any list could be maintained. Placement today is decided mostly by who is sending: whether the domain authenticates with SPF, DKIM and DMARC, how that domain and IP have behaved historically, and whether recipients open, reply, or delete. An established sender can write “free” without consequence. A cold domain cannot rescue itself with a thesaurus.

What actually decides where your email lands

In rough order of weight: authentication, sender reputation, recipient engagement, list hygiene, and then content — which includes wording, but also your text-to-image ratio, link quality and HTML structure. If you are landing in spam or Promotions and your copy is already clean, the cause is almost certainly further up that list.

How to use a list like this well

Treat it as a copy edit, not a compliance exercise. If a flagged phrase is doing real work in your sentence, keep it. If it is filler you reached for because it sounded like marketing, cut it — your writing improves either way. What you should never do is remove your unsubscribe link or postal address to “look less like a newsletter”. Those are legally required, and removing them causes the exact problem you are trying to avoid.

The real test

Words are one input. See the whole picture.

Forward a real email to the address below. In about 30 seconds you get the deliverability score, your SPF, DKIM and DMARC results, a placement forecast, and the three things most worth fixing.

Forward a test email here

demo-abc123@in.mailtester.ai

Report in ~30s · no login · one-time address, we never see your listNot ready? See a sample report first.

Example resultmailtester.ai/report/live

sara@lisbonletters.beehiiv.comreceived 14s ago · AI classifier verdict (no real send)

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

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

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.

Illustration contrasting a valid-address checkmark with an email landing in the inbox

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 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

Use both, actually — verify the list, then score the send.Address-validity tools: ZeroBounce, NeverBounce, MXToolbox

FAQ

Free Spam Words Checker

What are spam trigger words?: Phrases that appear far more often in spam than in legitimate mail, which filters learned to associate with it — things like 'no credit check', 'make money fast' or 'dear friend'. Rule-based scanners such as SpamAssassin still carry explicit rules for some of them, so the effect is real.
Will removing spam words fix my deliverability?: Usually not on its own. Word choice is a small input compared with authentication, sender reputation and how your recipients engage. If your emails are going to spam and your copy is already clean, the cause is almost always somewhere else.
Is this spam words checker free?: Yes, and there is no signup. Your copy is checked in your browser and is never uploaded, stored or sent anywhere.
Does the word 'free' send emails to spam?: No. 'Free' is ordinary marketing vocabulary and appears in enormous volumes of legitimate mail. Density is what matters — 'free' once in a real sentence is fine; six hard-sell phrases stacked together is a different signal.
How do I check where my email actually lands?: Forward a real send to a Mailtester address. In about 30 seconds you get a deliverability score, your SPF, DKIM and DMARC results, a placement forecast and the three fixes most worth making.

Built in the EU · GDPR by default

5,400+ emails tested

AI-classified across real Gmail, Outlook, and Yahoo inboxes.

Free · €0for unlimited scoring. €9.99 for AI deep-dives.

How it works

Three steps. About thirty seconds, end to end.

01~10 sec

Illustration of an email being forwarded into a testing mailbox

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

Illustration of inbox trays receiving and listening for the forwarded email

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

Illustration of a deliverability report card showing the score and fixes

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.

Keep going

Other free checks worth two minutes

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

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

€4.99one-time · 499 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. No card, no signup, no anything.