Email Spam Keyword Trigger Checker
Check email subject lines and copy for spam trigger words, calculate spam risk score, and improve inbox deliverability in Gmail and Outlook.
Email Copy & Subject Line
Interactive Highlighted Email Copy
Detected Spam Categories & Breakdown
Inbox Deliverability Recommendations
About this tool
How to use it
- Enter your email subject line in the subject input field (subject lines carry 2x to 3x spam filter penalty weight).
- Paste your email body copy into the text area or select a quick preset template.
- Select your filter strictness mode (strict for cold sales outreach, standard for newsletters, lenient for transactional).
- Review your 0 to 100 spam risk score, inspect highlighted trigger words in the live preview box, and replace flagged urgency and hype phrases with neutral alternatives.
Why it matters
Modern Bayesian email filters used by Gmail, Google Workspace, and Microsoft Outlook scan email text for high-pressure marketing patterns, artificial urgency, and financial trigger words. Exceeding a 1.5% spam trigger density or loading subject lines with sales clichés routes your campaigns directly into junk folders, causing severe open rate drops and damaging sending domain reputation.
When to use it
Use this tool before launching email marketing broadcasts, drafting cold B2B sales outreach sequences, preparing transactional onboarding emails, or diagnosing deliverability drops on an existing mailing list.
Good to know
Spam keyword scanning is one component of overall inbox placement. Sending domain authentication (SPF, DKIM, DMARC), recipient engagement, list hygiene, and sender IP reputation also directly influence whether emails reach the primary inbox.
Common questions
What makes an email trigger spam filters?
Email filters analyze a combination of keyword frequency, subject line phrasing, excessive capitalization or punctuation (such as !!! or $$$), image-to-text ratios, and domain authentication records. Overusing high-pressure urgency ('act now', 'expires tonight') or exaggerated financial promises ('100% free', 'make money') triggers automated spam flags.
Why do spam words in the subject line matter more than the body?
Subject lines receive disproportionately high algorithmic weighting in SpamAssassin and modern AI spam filters. A single aggressive phrase or ALL CAPS word in the subject line can push an email over the spam threshold even if the body copy is clean.
What is an acceptable spam trigger density?
Aim for a trigger density below 1.0% to 1.5% of total words. Having 1 or 2 common marketing words in a 300-word email is normal, but clustering multiple urgency and financial terms together in short paragraphs triggers heuristic spam alerts.
Can you use the word 'Free' without going to spam?
Yes, context matters. Occasional use of 'free trial' or 'feel free' in an authenticated email with strong sender reputation will not trigger spam filters on its own. Problems arise when paired with urgency modifiers like '100% free cash bonus act now'.
How can I improve my email deliverability besides fixing copy?
Ensure your domain publishes valid SPF, DKIM, and DMARC DNS records. Maintain clean recipient lists with double opt-in, warm up new sending IP addresses gradually, and include a prominent one-click unsubscribe link.