Paste your subject line and email body to get a heuristic spam score out of 10, with a plain-English breakdown of exactly which words and formatting choices are pushing the score up.
This checker uses a heuristic, rule-based approach modeled on the kinds of signals real spam filters weigh: a curated list of words and phrases long associated with promotional and scam email (free, act now, guarantee, risk-free and similar), the ratio of uppercase letters in your subject line, exclamation mark density, link density in the body, and whether basic compliance elements like unsubscribe language are present in a long message.
Each signal adds weight to a 0–10 score, with higher meaning riskier. This mirrors the spirit of tools like SpamAssassin, which score outgoing mail against a bank of rules, though this browser-based version uses a smaller, transparent rule set rather than a full Bayesian spam-filtering model, since a real filter also considers sender reputation, authentication and recipient engagement history — none of which can be evaluated from message text alone.
A high score doesn't mean your email will definitely be filtered, but it flags copy patterns that inbox providers' own filters are trained to weigh heavily. The findings list under your score names each specific issue — swap out flagged trigger phrases for plainer language, tone down excessive capitalization and punctuation, and make sure a long promotional message includes a visible way to unsubscribe.
Because inbox filtering models are retrained constantly and differ between providers, treat any single score as directional rather than absolute, and re-run a check after significant edits — a subject line rewrite or a change in link count can shift the score more than a single word swap.
No. Real inbox providers use proprietary machine-learning systems that also weigh sender reputation, authentication (SPF/DKIM/DMARC) and recipient engagement — factors this text-only tool can't see. Treat this score as a useful early warning on copy, not a guarantee of inbox placement.
Some everyday words like 'free' or 'guarantee' are common in legitimate business writing too, but they're also heavily represented in historical spam datasets, so filters still weight them. A flag here is a prompt to reconsider the phrase, not proof the email is spam.
No — for authentication checks like SPF and DKIM on a message you've received, use the Email Header Analyzer. For your own outgoing domain's mail server setup, use the MX Record Lookup as a starting point.
That helps, but the score reflects several independent signals — trigger words, capitalization, link density and structure. Address the specific findings listed rather than tweaking one factor in isolation.
No tool can guarantee inbox placement. A low score means your copy avoids the most common textual red flags, which is a meaningful step, but deliverability also depends on your domain's sending reputation and authentication setup.