Email Specs
Spam Trigger Words Reference
Spam word lists are the most overrated artefact in email marketing. Modern filters weigh sender reputation, authentication and engagement far above vocabulary. I keep this list because the patterns still matter in combination, not because the word free will send you to junk.
| Pattern | Examples | Risk level |
|---|---|---|
| Urgency and pressure | Act now, urgent, limited time only | Low on its own, higher in combination |
| Money and income claims | Make money fast, double your income | High |
| Free and prize language | Free gift, you are a winner, no cost | Moderate |
| Financial and credit terms | No credit check, refinance, eliminate debt | High in bulk sends |
| Regulated claims | Miracle cure, lose weight fast | High |
| Formatting patterns | ALL CAPS, excessive exclamation marks, red text | Moderate |
| Structural patterns | Single image email, many links, hidden text | High |
| Signal | Weight | How to improve it |
|---|---|---|
| Authentication | Critical | SPF, DKIM and DMARC aligned and passing |
| Sender reputation | Critical | Consistent volume, low complaints |
| Engagement | High | Send to people who open and click |
| Complaint rate | High | Keep below roughly 0.1 percent |
| List hygiene | High | Remove hard bounces and long inactives |
| Content and vocabulary | Low to moderate | Write plainly, avoid stacked triggers |
Notes
If your email lands in spam, the cause is almost never a word. It is authentication that is not aligned, a list that includes addresses which never engaged, or a complaint rate that crossed a threshold. Fix SPF, DKIM and DMARC first, then look at who you are sending to, and only then edit the copy.
Vocabulary risk is cumulative rather than absolute. One instance of free in a sentence that reads naturally is invisible. A subject line with free, urgent, an exclamation mark and capitals together forms a pattern that matches the training data for actual spam, and that combination is what gets scored.
Structure matters more than words. A single image email with one link and almost no text is a classic evasion pattern, and filters treat it accordingly. A balanced text to image ratio with a plain text alternative part is both better for readers and better for placement.
Filtering is model driven and changes continuously at Gmail, Microsoft and Yahoo, including bulk sender requirements introduced in recent years. Verify against the current sender guidelines from the mailbox providers rather than treating any word list as authoritative.
Frequently asked questions
Will using the word free send my email to spam?
No. On its own it is a non event. It only contributes when stacked with other urgency and money signals in a message from a sender with weak reputation.
What is the single most effective deliverability fix?
Correct, aligned authentication with a DMARC policy, followed by removing subscribers who have not engaged in a long time. Those two changes fix more inbox problems than every copy edit combined.
Does a spam score checker predict inbox placement?
Only loosely. Those tools score content, and content is the smallest input. Use seed testing and provider postmaster tools for a realistic picture.
Official sources
Platforms change specifications without notice. Check the primary documentation before a launch that depends on an exact value.
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