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Free Email Deliverability Tool

Email Spam Checker

Paste your subject line and body to get an instant spam score. Catch spam trigger words, formatting red flags, link density issues, and length problems before they hurt your cold email deliverability.

Everything runs locally in your browser. We never store or transmit your email content.
Example OutputThis is a preview. Paste your own email above to test.
Subject Line
URGENT! Free money inside — click now!!
Email Body
Congratulations! You've been selected to claim a special bonus. Act now — this limited-time offer expires today. Click here to get your free gift!
42
High Risk
Issues Detected
❌ Multiple spam trigger words (urgent, free, congratulations, claim, bonus, free gift)
❌ Subject contains ALL CAPS word ("URGENT")
❌ Subject contains multiple exclamation marks (!!)
❌ Body uses excessive urgency language (act now, limited-time, expires today)
!
⚠ Subject too short (37 chars; ideal 30-50 with substance)
Target score by send type
Cold Outreach
85+
Newsletter
80+
Transactional
90+
Promo
75+

How to use the spam checker in 3 steps

Step 01
Paste subject and body

Drop in the exact subject line and message body you plan to send. The tool runs fully in your browser — nothing is stored or transmitted.

Step 02
Run instant spam scan

Our engine scores 8 deliverability dimensions in under a second — spam words, all-caps ratio, exclamation count, link density, length, and more. Pair with email verifier to confirm the recipient address is valid.

Step 03
Fix issues and send

Review the issue list, apply the suggested fixes, and rescan until you hit your benchmark score. Need an AI-written rewrite? Try our cold email generator.

What we check

8 deliverability checks based on Gmail, Outlook, and SpamAssassin filter heuristics

🛡️
Spam trigger word detection

Scans your subject and body against a dictionary of 40+ known spam trigger words across money, urgency, clickbait, and adult-pharma categories. Pair with bulk email verifier for full list hygiene.

📏
Subject length scoring

Subjects under 30 or over 65 characters get flagged. The ideal range (30-50) maximizes mobile preview and avoids truncation across Gmail, Outlook, and Apple Mail.

🔗
Link density check

Too many links is one of the strongest spam signals. We count http(s) URLs and warn when density exceeds inbox-safe ratios, especially for cold outreach.

📊
Formatting red flags

Catches all-caps ratio, runs of !!! or ??? , and all-caps words — patterns that ESP filters punish hard. Build healthier lists with our email finder to keep bounce rates low.

Who uses this spam checker

Cold email senders

Cold outreach lives or dies on the first impression. Run every template through the spam checker before launching a sequence. Combine with our cold email generator for a complete pre-send workflow.

Newsletter and marketing teams

Promo campaigns are spam-trigger magnets. Use the checker to validate copy edits before queuing the send, and confirm subscriber addresses with our bulk email verifier first.

Sales reps and SDRs

Personalized cold emails still hit the spam folder if the copy looks promotional. Score every variation and find verified inbound contacts with our email finder.

Transactional and lifecycle email

Welcome, receipt, and reset emails must hit the primary inbox. The checker validates template copy stays clean of trigger words, all-caps, and excessive links.

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FAQ

Get answers to common questions about Lessie AI.

What is an email spam checker?

An email spam checker analyzes your email content — both subject line and body — against the same heuristics ESPs and spam filters use, then produces a deliverability score and a list of issues to fix. Our checker scores 8 dimensions including spam trigger words, length, all-caps ratio, exclamation count, link density, word count, question marks, and all-caps words.

How does the spam score work?

We start every email at 100 points and deduct based on the severity of each issue detected. Mild problems (e.g., a slightly long subject) deduct 5-8 points; serious issues (e.g., 3+ spam trigger words or runs of !!!) deduct 15-20. Scores 90+ are excellent for any send type, 70-89 are good for most use cases, and below 70 needs revision before sending.

What words trigger spam filters?

The most common spam trigger words fall into four buckets: money (free, cash, no cost, 100% free), urgency (act now, urgent, limited time), clickbait (congratulations, winner, prize, claim), and affiliate or adult-pharma (viagra, weight loss, pre-approved). Our checker scans 40+ of these and shows you exactly which words it found. Pair this with our email verifier to confirm recipient addresses are valid.

Is this email spam checker really free?

Yes — 100% free with no signup, no usage limit, and no data sent to a server. The entire analysis runs in your browser, so your email copy never leaves your device. We built this tool to help cold email senders, SDRs, and newsletter creators ship better-performing campaigns.

What is a good spam score for cold email?

For cold outreach, aim for 85 or higher because cold email starts with zero sender reputation and lower trust. Newsletters and promo emails can perform well at 75-80 because list-based send patterns and engaged subscribers help offset minor red flags. Transactional emails should target 90+ since they need near-perfect inbox placement.

How is this different from a deliverability test?

A full deliverability test (e.g., Mail-Tester, GlockApps) sends a real email to seed inboxes and checks SPF, DKIM, DMARC, IP reputation, and inbox placement. Our spam checker is a faster, free pre-flight: it scores only the content layer (copy, formatting, links) so you can iterate before you spend a deliverability test credit. For full sender-side coverage, combine our checker with our bulk email verifier to clean your list first.

Can I use this for HTML or templated emails?

Yes. Paste the rendered plain-text version of your HTML email (or just the visible copy) into the body field. The checker analyzes the words, links, and formatting your recipient actually sees, which is what spam filters score most heavily. Discover verified prospects to test your templates with via our email finder.

Send Cold Email That Lands in the Inbox