412 Spam Words to Avoid in Emails

Spam keywords are trigger phrases that spam filters flag as harmful or fraudulent. Context matters significantly — using “risk free” in a product pitch differs substantially from casual conversation language.

What Are Spam Keywords?

Email providers use sophisticated algorithms to detect patterns associated with spam. When your email contains enough of these trigger words, the likelihood of landing in the spam folder increases dramatically.

The key insight: emails that read like advertisements face higher spam folder risk. Maintaining strong campaign performance metrics provides more leeway when using these words, but it’s best to avoid them altogether in cold outreach.

Categorized Spam Words (412 total)

We’ve organized problematic terms into seven categories:

Subject Line Triggers (141 words)

Words commonly flagged when used in subject lines, including phrases like “act now,” “limited time,” “free,” “congratulations,” “you’ve been selected,” and similar urgency or reward language.

Urgency-Focused Language (49 words)

Phrases that create artificial time pressure: “hurry,” “expires,” “deadline,” “last chance,” “don’t miss out,” “once in a lifetime,” and related terms.

Promise-Based Phrases (36 words)

Language that makes unrealistic commitments: “guaranteed,” “risk-free,” “no obligation,” “100% satisfied,” “double your money,” and similar assurances.

Commercial Terminology (69 words)

Sales-heavy vocabulary: “buy now,” “discount,” “lowest price,” “bargain,” “order today,” “special promotion,” and related commercial language.

Financial Language (65 words)

Money-related triggers: “earn money,” “cash bonus,” “investment,” “credit card,” “income,” “profit,” “financial freedom,” and similar terms.

Email Marketing Terms (31 words)

Phrases associated with mass email: “click here,” “subscribe,” “unsubscribe,” “opt-in,” “bulk email,” “email marketing,” and related terms.

Job and income-related triggers: “work from home,” “be your own boss,” “unlimited income,” “home-based,” and similar phrases.

How to Detect Spam Words

Use email tools like Mailshake that automatically flag spam words before campaign launch. This catches issues before they affect your deliverability.

Additional Red Flags

Beyond vocabulary, other deliverability issues include:

Lacking opt-out mechanisms
Excessive formatting (bold, colors, ALL CAPS)
Multiple links or images
Sending from unwarmed domains
Poor list hygiene (high bounce rates)

Practical Takeaway

Write your cold emails like you’d write to a colleague — conversational, specific, and free of marketing language. The goal is to sound human, not promotional.