You thought you had created a killer email, but it ended up in the spam folder. Despite your best efforts to create engaging content, are your open and click-through rates not where they should be? The culprit could be spam trigger words. 

These words are like red flags to email service providers (ESPs), signaling that your email could be spam. Well, this gets your emails filtered out of the inbox.

In 2025, email deliverability remains a critical aspect of successful email marketing. Now that we are completely moving away from open rates tracking, you must be more careful with your email deliverability.

To maximize your email’s potential and ensure it reaches your recipients, it’s crucial to understand how to avoid spam trigger words like “discount”, “exclusive offer”, “urgent action needed”, and how they can impact your email campaigns. 

In this detailed guide, we’ll explain what spam trigger words are, why they matter, and how to avoid them in your email marketing strategy. We’ll also cover best practices to ensure your emails pass through spam filters and land in your audience’s inbox.

What Are Spam Trigger Words?

Spam trigger words are words and phrases that email service providers (ESPs) and spam filters identify as signals of unwanted or unsolicited email. 

These words often appear in spam emails or overly aggressive sales pitches, and thus, ESPs use them as a basis to filter out potentially harmful content.

One in six emails land in spam folders, translating to around 16% of emails. This was according to a study done by Validity in 2023.

Why Are They Problematic? 

When your email contains too many of these words or if they appear in combination with other suspicious elements (like a poorly formatted email or incorrect authentication), it can be flagged as spam. This hurts your deliverability, meaning your emails might end up in your recipients’ spam folders instead of their inboxes.

Here’s why avoiding spam trigger words is essential:

• Reputation Damage: Hitting too many spam filters can lower your sender's reputation, making it harder for future emails to get delivered.
• Lower Engagement: Emails caught by spam filters don’t get read, which affects your open rates, click-through rates, and overall engagement.
• Reduced Conversions: The fewer emails that reach inboxes, the fewer chances you have to convert leads or engage with customers.

Why Avoiding Spam Trigger Words Is Crucial for Email Marketing

Your emails won’t reach your audience’s inbox if the spam trigger words interfere. Gmail, Outlook, Yahoo, and other email providers have designed complex algorithms to analyze your entire email content and detect spam words.

So, if you want a successful email campaign, you must avoid spam trigger words. If you are not yet convinced, here are a few other things you should know.

Key Reasons to Avoid Spam Trigger Words:

1. Maintain High Email Deliverability
   When ESPs detect spam words in your subject line or body text, it raises a red flag. If these words are combined with other spammy signals (like poor HTML, missing authentication, or high bounce rates), your emails may be sent straight to the spam folder. Use language that doesn’t trip these filters to maintain high email deliverability.
2. Improve Open and Click Rates
   High deliverability ensures that your emails are seen, which increases the likelihood that your recipients will open them. More opens mean more engagement opportunities, which can improve your click-through rates (CTR).
3. Avoiding Sender Reputation Damage
   If your emails are consistently marked as spam, your sender's reputation suffers. This reputation is like a credit score for email marketing—once it’s damaged, it’s hard to rebuild. Avoiding spammy language helps you preserve your credibility with ESPs.

Avoiding such spam trigger words can significantly improve email deliverability, leading to better engagement, higher open rates, and stronger campaign conversions.

Common Spam Words to Avoid in Email in 2025

While every ESP has its filtering algorithm, several words consistently cause problems across platforms. Here are the spam words to avoid in email content, particularly in your subject lines and call-to-action (CTA) buttons.

Categories of Spam Trigger Words:

1. Sales and Promotion
   • "Buy now"
   • "Discount"
   • “Act now”
   • “Order now”
   • "Free"
   • "Special promotion"
   • "Exclusive deal"
   • "50% off"
2. Money and Finance
   • "Earn money"
   • "Get rich quick"
   • "Investment opportunity"
   • "Limited-time offer"
   • "Cash bonus"
   • “Save big money”
   • “Lowest price”
   • “No hidden costs”
3. Urgency and Scarcity
   • "Act now"
   • "Urgent"
   • "Limited time"
   • "Hurry!"
   • "Don't miss out"
   • “This won’t last”
   • “Final chance”
   • “Last chance”
   • “Offer expires”
4. Risky and Guarantee Language
   • "Risk-free"
   • "Guaranteed"
   • "100% satisfaction"
   • "No cost"
   • "Money-back guarantee"
5. Health and Wellness
   • "Lose weight fast"
   • "Cure"
   • “Burn fat”
   • “Secret formula”
   • "Miracle"
   • "No prescription needed"

These are just a few examples of spammy words that ESPs flag. Use them sparingly, and make sure the context feels natural and non-deceptive when you do.

How to Identify Spam Trigger Words in Your Emails

While avoiding spam words is critical, manually identifying every potential issue can be time-consuming. Thankfully, tools are designed to scan and flag spam trigger words, giving you insights into how spammy your email might appear to ESPs.

Tools to Detect Spam Trigger Words:

1. MailTester
   This tool allows you to send a test email to an address. It will evaluate the content for spammines, identify problematic words, and give you suggestions for improving deliverability.
2. GlockApps
   GlockApps provides email deliverability testing and spam filter testing. It helps marketers check how their emails are being perceived by spam filters and identifies content that could trigger spam flags.
3. SpamAssassin
   SpamAssassin scores your email based on its likelihood of being flagged as spam. It’s useful for identifying words or phrases that might hurt your deliverability.

Using these tools regularly before sending out email campaigns will help you catch issues early and ensure you stay compliant with ESP standards.

Strategies to Avoid Spam Filters Without Losing Your Message

While spam trigger words are important to avoid, your email campaigns don't have to lose their effectiveness or persuasive power. 

Here are some actionable strategies to avoid spam filters while maintaining engaging content.

1. Use Alternative Phrasing

Instead of relying on spammy words like "Buy now" or "Free," consider alternative phrasing that conveys urgency or value without triggering spam filters. For example:

• Instead of "Free trial," use "Complimentary trial" or "No-cost trial."
• Instead of "Limited-time offer," use "Exclusive offer for subscribers."

2. Write for Engagement, Not Just Sales

Emails packed with promotional language are more likely to trigger spam filters. Instead, focus on creating content that informs, educates, or entertains. Emails that provide value beyond sales pitches are more likely to bypass spam filters and engage readers.

3. Personalize Your Content

Personalization helps reduce the risk of being marked as spam. Emails addressed directly to the recipient and based on their behavior (e.g., browsing history, past purchases) are less likely to be flagged. Use personalization tokens like:

• First name in the subject line
• Customized product recommendations

4. Maintain a Healthy Sender Reputation

A strong sender reputation increases the chances that your email will land in the inbox, even if you use borderline spammy words. Keep your sender reputation high by:

• Sending emails to active, engaged recipients
• Cleaning your email list regularly
• Ensuring your bounce rate stays low

Best Practices to Improve Email Deliverability

Spam trigger words are just one piece of the puzzle regarding email deliverability. Here are some additional best practices to ensure your emails reach their intended audience.

1. Authenticate Your Emails

Use proper email authentication protocols such as SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), and DMARC (Domain-based Message Authentication, Reporting & Conformance). These protocols tell ESPs that you’re a legitimate sender, which increases your chances of bypassing spam filters.

2. Use a Clean Email List

Sending emails to outdated, invalid, or disengaged contacts increases the likelihood of being flagged by spam filters. Regularly clean your list by removing inactive subscribers and invalid email addresses to improve your deliverability rate.

3. Keep Your Design Simple

Avoid overly complex designs and use HTML wisely. Emails that are too image-heavy or contain excessive links can appear spammy. Maintain a balance of text and visuals, and ensure your emails are mobile-optimized for a seamless user experience.

4. Encourage Engagement

High engagement rates signal to ESPs that recipients want your emails. Encourage replies, clicks, and interactions in your emails by:

• Asking questions or seeking feedback
• Including polls or surveys
• Offering exclusive content that prompts action

Tools to Improve Email Deliverability and Spot Spam Trigger Words

As spam filters become more advanced, it’s crucial to use the right tools to stay ahead. Here are some of the best tools available in 2025 to help improve email deliverability and avoid spam triggers.

Smartlead

Smartlead is a comprehensive cold email tool that helps with automation and enhances email deliverability. Smartlead helps marketers avoid spam traps and trigger words with built-in features that monitor email health and performance. Its multi-inbox rotation and personalized email features help distribute emails across multiple addresses, lowering the risk of hitting spam filters. It also has email warm-up tools to increase your sending reputation and gradually prevent deliverability issues. 

ZeroBounce

ZeroBounce specializes in email validation and list cleaning, ensuring that your email list is accurate and free of spam traps or invalid addresses.

NeverBounce

Another email validation tool, NeverBounce, helps marketers keep their lists clean by identifying problematic emails, which improves overall deliverability.

Google Postmaster Tools

Google’s tool helps monitor your sender reputation and provides insights into email delivery issues, such as why certain emails are landing in the spam folder.

SendGrid

SendGrid offers robust email marketing services with built-in deliverability tools to help you monitor, optimize, and improve your email campaigns.

Wrapping Up

Avoiding spam trigger words is crucial to running a successful email marketing campaign in 2025. By understanding which words to avoid and using the strategies outlined here, you can greatly improve email deliverability and ensure your messages reach your audience’s inbox.

By following best practices like list cleaning, email validation, and strong sender authentication, you’ll avoid spam filters and increase engagement with your subscribers.

Ready to boost your email deliverability? Check out our free 14-day trail of Smartlead to boost your email deliverability stats.

‍