Warming up
Free tool
Free cold email spam word checker.
Paste your cold email subject line and body to catch spam-trigger phrases before you hit send. No signup, nothing stored — runs entirely in your browser.
How the checker works
The checker scans your subject line and body against a curated list of phrases known to trigger spam filters and Gmail/Outlook's promotions classifier — things like "act now", "100% free", and "click here" — plus subject-line formatting issues like ALL CAPS or repeated punctuation. Each match adds to a 0-100 risk score.
Honest caveat: modern Gmail and Outlook filters are ML-based and mostly don't care about individual words like "free" anymore — see chapter 7 of our deliverability guide on which content patterns are real signals versus 2008-era myths. Link-to-text ratio, sender authentication, and reputation matter far more than any single word — check those with our free deliverability checker and email HTML checker. For the full cold outbound setup — domain, authentication, and warmup — see our cold email setup guide.
Common spam-trigger categories
The checker groups flagged phrases into four categories. Knowing which one a match falls into tells you whether it's worth rewriting or safe to ignore in a one-to-one cold email:
- Urgency: "act now", "limited time", "don't miss out", "expires soon". These read as mass-blast pressure tactics — the opposite of a genuine one-to-one note, so worth cutting regardless of filter risk.
- Money / free: "100% free", "guaranteed", "make money", "no cost". Low filter risk on their own in 2026 (see the FAQ below), but they still make a first-touch email read as promotional.
- Exaggerated claims: "best in the world", "risk-free", "instant results", "once in a lifetime". These hurt reply rate more than deliverability — recipients skim past superlatives.
- Formatting: ALL CAPS subject lines, repeated punctuation ("!!!", "???"), excessive emoji, or a subject line that's mostly a link. These are the patterns legacy keyword filters still weight most heavily, so they're the highest-value fixes if your score comes back high.
Frequently asked questions
What does this tool check?
It scans your cold email subject line and body for wording and formatting that reads as spammy to a human recipient — phrases like "act now" or "100% free", ALL CAPS, and repeated punctuation — plus flags basic keyword filters some legacy mail systems still use.
Is "free" actually a spam trigger word in 2026?
Less than you'd think. Modern Gmail and Outlook filters are ML-based and mostly don't care about individual words like "free" — that's a 2008-era rule. What they weight far more heavily is link-to-text ratio, sender authentication (SPF/DKIM/DMARC), and recipient engagement history. This tool is useful for catching copy that reads as spammy to a human, and for the handful of legacy filters that still do keyword matching — but treat a clean score as a courtesy check, not a deliverability guarantee. See our full deliverability guide for what actually moves the needle.
How is this different from a generic email spam checker?
Most spam checkers are built for newsletters and marketing blasts. This one is tuned for cold outreach copy — first-touch and follow-up emails sent one-to-one from a personal domain, where the failure modes (over-salesy openers, fake urgency, oversized links) look different from a bulk campaign.
Does a low score guarantee inbox placement?
No. Sender reputation, authentication, and engagement history matter far more than copy. Check those with our free deliverability checker and email HTML checker.
Is this free to use?
Yes, no signup or email required. Nothing you paste is stored — the check runs entirely in your browser.
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Placement
Wording is the last ten percent.
Trigger words matter, but they are scored against a sender that already has a reputation. Clean copy from an unauthenticated, cold domain still lands in spam; ordinary copy from a warmed, authenticated one usually does not.
Fix the words here, then fix the sender — inbox placement and reply rate are the two numbers that tell you whether it worked.
Want your whole domain monitored, not just one email?
InboxPulse checks SPF, DKIM, DMARC, and MX every day, and Warmflow automates warmup to build the sender reputation that copy alone can't fix.