100 Spam Words to Avoid to Stay Out of Email Spam Folders

You wrote a good email. Your subject line is punchy. Your offer is real. But it never reached the inbox.

Spam filters scan your content before your subscribers ever see it. They look for patterns — specific words and phrases that correlate with the kind of emails people mark as spam. Use too many, and your email goes straight to junk, regardless of how legitimate it is.

This post gives you 100 of the most common spam trigger words, organized by category. Know what to watch for before you hit send.

What are spam trigger words?

Spam trigger words are keywords and phrases that spam filters treat as red flags. They tend to appear in emails people mark as spam: phishing attempts, get-rich-quick schemes, unsolicited promotions, and overpromising offers.

According to research by Litmus, email deliverability problems affect roughly 1 in 6 emails globally. Spam trigger words are one of the most controllable variables in that equation.

The filter logic has evolved. Modern spam filters don’t automatically block an email for containing one trigger word. They’re scoring systems — you accumulate points for each flag, and once your score crosses a threshold, the email is filtered.

Use a single phrase like "act now" in context, and you’re probably fine. Stuff five urgency phrases into a subject line while using all caps and a red font, and you’ve built a spam email. The words matter less than the pattern they form.

Why spam words tank your deliverability

Deliverability isn’t just about landing in the inbox today. Inbox providers like Gmail and Outlook track sender reputation over time — and repeated spam filter hits compound.

Every email you send that triggers a filter contributes to a lower sender reputation score. Lower scores mean more of your future emails get filtered, even if those future emails are clean. The damage is cumulative.

Emailtooltester’s 2024 deliverability benchmarks showed that average deliverability across major email platforms sits at 89.6%. That means roughly 1 in 10 emails doesn’t reach the inbox under normal conditions. Spam trigger words push you further from that benchmark, not closer.

The practical implication: audit your email content proactively, not after your open rates drop.

100 spam words to avoid

These are organized into four categories: exaggerated claims, urgency and pressure, shady behavior, and financial jargon. Most of the highest-risk words appear in subject lines — where they’re most visible to spam filters and human readers alike.

Category 1: Exaggerated claims and promises

These words signal that something sounds too good to be true. Spam filters have learned this because it usually is.

100% free
100% satisfied
Additional income
Best price
Big bucks
Cash bonus
Double your cash
Double your income
Earn extra cash
Earn money
Extra cash
Extra income
Fast cash
Financial freedom
Free gift
Free money
Full refund
Giveaway
Guaranteed
Incredible deal
Lowest price
Make money
Miracle
Money back
Once in a lifetime

These phrases appear almost exclusively in spam. There’s rarely a legitimate use case for "double your cash" in a real product email. If your offer is genuine, describe it with specifics — not superlatives.

Category 2: Urgency and pressure tactics

These words manufacture pressure. Spam filters recognize them because legitimate senders don’t usually need to beg.

Act now
Apply now
Call now
Click below
Click here
Do it today
Don’t delete
Exclusive deal
Get it now
Get started now
Important information regarding
Instant
Limited time
New customers only
Order now
Please read
See for yourself
Sign up free
Take action
This won’t last
Urgent
What are you waiting for?
While supplies last
Winner
You have been selected

"Click here" and "act now" are especially common in phishing emails. Even legitimate senders who use these habitually accumulate spam risk. Replace them with specific calls to action: "See your dashboard," "Start your free trial," or "Review the update."

Category 3: Shady or unethical-looking behavior

These words trigger filters because they appear in emails that try to avoid detection — or sell something people don’t want.

Bulk email
Buy direct
Cancel at any time
Confidentiality
Congratulations
Dear friend
Direct email
Direct marketing
Hidden charges
Internet marketing
Lose weight
Mass email
Meet singles
Multi-level marketing
No catch
No cost
No credit check
No fees
No gimmick
No hidden costs
No hidden fees
No obligation
No questions asked
No strings attached
Not junk

The irony of phrases like "not junk" and "this isn’t spam" is that only spammers say them. Any email that feels the need to disclaim its own legitimacy is already in trouble. Remove these entirely.

Category 4: Financial jargon and legal terms

These phrases have high association with financial spam, MLM schemes, and loan scams.

Accept credit cards
Bargain
Billing
Bonus
Cards accepted
Cash
Certified
Cheap
Clearance
Compare rates
Credit card offers
Deal
Debt
Discount
In accordance with laws
Income
Investment
Join millions
Loans
Mortgage rates
Offer
Pre-approved
Refinance
Terms and conditions
Work from home

Many of these words are innocuous in isolation — "discount" and "offer" appear in perfectly legitimate retail emails. But paired with other spam signals (excessive caps, no unsubscribe link, poor sender reputation), they increase your filter score. The goal is to minimize your total risk, not just avoid the worst offenders.

Why each category carries different risk

Not all four categories are equal in terms of filter severity. Understanding the risk tier helps you prioritize what to fix first.

Exaggerated claims are the highest risk. Phrases like "miracle," "guaranteed," and "100% free" have appeared in spam for decades. Spam filter training data is saturated with these terms, and their presence in your copy creates an immediate negative signal — especially in subject lines.

Urgency phrases are medium-high risk, and heavily context-dependent. "Limited time" in a Black Friday campaign from a known brand will usually land fine. "Limited time" from a new sender domain with a cold list is a red flag. The same phrase triggers differently based on your sender reputation.

Shady behavior words are often self-defeating. If you’re writing "no catch" or "this isn’t spam," ask yourself why those phrases feel necessary. Legitimate emails don’t need to disclaim their own legitimacy. Removing them improves both your spam score and your credibility.

Financial jargon carries medium risk on its own but amplifies other signals. "Discount" paired with good authentication and a strong sender reputation is fine. "Discount + act now + cash + guaranteed" in the same email is a different matter. Financial terms compound quickly.

How spam filters actually score your emails

Spam filtering is a multi-factor scoring system, not a simple word blocklist. Major inbox providers like Gmail and Outlook use machine learning models trained on billions of classified messages.

The inputs to that model include your sender reputation (IP and domain), authentication results (SPF, DKIM, DMARC), list engagement rate, bounce rate, complaint rate, and content signals — including but not limited to spam trigger words.

Content accounts for a portion of the total score, not the whole thing. A sender with excellent reputation and high engagement can get away with more aggressive copy. A new sender with no track record has no buffer — every signal matters.

SpamAssassin, the open-source filter that underlies many corporate mail servers, assigns point values to specific patterns. Using all caps in a subject line might add 0.8 points. Using "Click here!" might add 0.5 points. The total threshold for filtering is typically 5 points. You can build to that threshold quickly.

The practical lesson: your spam word audit is most important if your sender reputation is weak or new. As your reputation strengthens through consistent deliverability and high engagement, content-level signals become a smaller share of your total score.

Context matters: when trigger words are fine

Not all 100 words on this list will flag your email every time. Spam filters score holistically.

A transactional email from a well-established sender domain that says "your invoice is ready — no additional fees apply" will deliver fine even though it contains "fees." The sender reputation, HTML quality, authentication setup, and list hygiene all factor into the score alongside content.

What spam filters are actually looking for is a combination of signals. SpamAssassin’s scoring system, one of the most widely used open-source spam filters, assigns point values to dozens of variables simultaneously. A single trigger word rarely crosses the threshold alone.

The rule of thumb: the more trigger words you stack — especially in subject lines — the higher your risk. Subject lines are disproportionately weighted by spam filters because they’re the first thing scanned.

5 deliverability tips that matter as much as avoiding spam words

Removing spam words is necessary but not sufficient. These practices have an equal or greater impact on inbox placement:

1. Authenticate your sending domain

SPF, DKIM, and DMARC are email authentication standards that tell inbox providers your domain is legitimate. Without them, even clean emails can land in spam.

All three should be configured before you send your first campaign. Most email platforms walk you through this during onboarding, but it’s worth verifying independently with a tool like MXToolbox.

2. Clean your list regularly

Every inactive or invalid email address you send to reduces your engagement rate. Lower engagement rates signal to inbox providers that recipients don’t want your emails — even if the content is good.

Remove subscribers who haven’t opened in 90–180 days. Set up suppression lists for hard bounces immediately. High bounce rates are one of the fastest ways to damage sender reputation.

3. Use a warm-up period for new domains

Sending high volumes from a brand-new domain triggers immediate suspicion. Domain warming — gradually increasing volume from a new sending domain over several weeks — gives inbox providers time to establish that you’re a legitimate sender.

Skip the warm-up period, and even well-crafted emails will underperform from day one.

4. Maintain a healthy sender score

Your sender score reflects the reputation of your sending IP address based on complaint rates, bounces, and blacklist status. Low scores directly reduce inbox placement rates across all major providers.

Monitor it monthly. Address spikes in complaints or bounces immediately rather than letting reputation decay compound.

5. Match your send frequency to engagement

Sending too frequently to disengaged subscribers is one of the most common deliverability mistakes. Recipients who stop opening but don’t unsubscribe still count against your engagement metrics.

Segment your list by engagement level. Send more frequently to active subscribers. Reduce frequency for inactive segments, and run a re-engagement campaign before suppressing them entirely.

Frequently asked questions

Do spam words matter more in subject lines or email body?

Both matter, but subject lines carry more weight. Spam filters scan them first, and humans see them first too — a suspicious subject line gets reported as spam before it’s even opened. Keep subject lines especially clean of trigger words.

Can I use the word "free" in emails?

Yes, but carefully. "Free" on its own, in context, from a good sender domain, is rarely a problem. "Free gift + sign up free + 100% free + free consultation" in the same subject line is a different story. Limit "free" usage and balance it with specifics about what’s actually being offered.

Does using all caps trigger spam filters?

Yes. All-caps subject lines or heavy use of all caps in body text are classic spam signals. They’re the written equivalent of shouting — and spam filters treat them that way. Use capitalization normally.

Do spam filters check links inside emails?

Yes. Links to domains with poor reputations or short-link redirects from suspicious domains can trigger filters independently of your word choice. Always link to well-known, authenticated domains. Avoid URL shorteners where possible, as they obscure the final destination.

How do I test my emails for spam before sending?

Tools like Mail-Tester and GlockApps let you send a test email and receive a spam score. They check content, authentication, sender reputation, and link quality in a single pass. Run them before every major campaign, not just when something breaks.

Should I remove "unsubscribe" links to avoid that trigger word?

Never. The word "unsubscribe" doesn’t trigger spam filters — removing your unsubscribe link does. The CAN-SPAM Act legally requires a clear unsubscribe mechanism in every commercial email. Inbox providers also use the presence of a working unsubscribe link as a positive signal that you’re a legitimate sender. Always include it.

Does plain text email avoid spam filters better than HTML?

Sometimes. Plain text emails have fewer potential trigger points (no broken HTML, no suspicious image hosting, no link masking). But modern spam filters are equally capable of evaluating plain text content, and HTML emails from strong senders perform fine. The better question is whether your HTML is well-coded — broken HTML is a separate spam signal that can flag an otherwise clean email.

What’s a good unsubscribe rate to maintain inbox placement?

HubSpot’s email benchmark data puts average unsubscribe rates at around 0.5% per campaign. Staying below 0.1% per send is generally a good target. Consistently high unsubscribe rates suggest your content isn’t resonating — which is both a business problem and a deliverability signal.

Conclusion: clean copy is a deliverability practice

Spam trigger words are a symptom, not the disease. The underlying issue is usually a combination of weak list hygiene, poor sender reputation, and content that mimics what real spammers write.

Fix the underlying practices — authenticate your domain, clean your list, monitor your sender score, and match frequency to engagement — and most spam word concerns take care of themselves. The word list above helps you eliminate unnecessary risk from your copy, but it doesn’t replace the infrastructure work.

If you’re sending behavioral emails triggered by real user actions — onboarding sequences, activation nudges, re-engagement flows — the spam word problem largely disappears. Relevant, expected emails don’t read like spam. Platforms built for that kind of event-triggered messaging help you send content that’s genuinely wanted, which is the strongest deliverability signal of all.

Want to send behavioral emails that land in the inbox? Vero’s free trial lets you test event-triggered campaigns with your real data — no credit card needed.