Spam Triggers That Are Hurting Your Email Open Rates

Email Marketing

Feb 16

Spam triggers are one of the most common reasons emails underperform, sending emails straight to the spam folder, never to be opened. Luckily, they’re pretty well known and easy to avoid once you know what they are!

In this post, I’ll break down what spam triggers are, how to prevent your emails from going to spam, and provide a list of the most common spam words to avoid when writing your emails!

What are Spam Triggers?

To understand spam triggers, we must first understand spam filters, which are an automated system that identifies and blocks unwanted or malicious emails from reaching a user’s inbox. The goal of spam filters is to protect email users from junk mail, phishing, and malware by analyzing sender information, keywords, links, and user behavior to sort legitimate emails from junk.

These filters come installed in email providers and use methods like blacklists, whitelists, rule-based checks, and machine learning to improve accuracy and keep inboxes clean and secure. In running checks, spam filters sort through common spam triggers that, if present, send an email straight to the spam folder. They don’t pass go, and they definitely don’t collect $200. (That’s a Monopoly reference just to be clear.)

In short, spam filters check for:

The use of certain words
Links to sketchy websites
ALL CAPS MESSAGES
Colorful and different-sized fonts
Broken HTML code
Emails without an unsubscribe button (This is actually illegal. Don’t do it.)

Spam triggers, or spam trigger words, are specific keywords or phrases that email providers see as red flags, causing them to mark your emails as spam.

The good news is that email filters are becoming more advanced and look at authentication, sender reputation, and engagement, as well as the specific words being used. Therefore, there are a few ways you can improve your email deliverability, even if a few spam words slip through.

Tips to Boost Deliverability and Avoid the Spam Folder

Avoiding spam triggers isn’t just about deleting a few “bad words” from your emails. Modern inbox providers look at the entire picture of how you send emails, who you send them to, and how people interact with them. Here’s how to improve deliverability in a way that actually moves the needle.

1. Ensure You Have Email Authentication in Place

Email authentication is one of the biggest (and most overlooked) factors in deliverability. Without it, inbox providers can’t verify that your emails are truly coming from you, which makes them far more likely to be flagged as spam.

At a minimum, your domain should have these three authentication records set up:

SPF (Sender Policy Framework): Confirms which servers are allowed to send emails on your behalf
DKIM (DomainKeys Identified Mail): Adds a digital signature to your emails to verify authenticity
DMARC: Tells inbox providers what to do if an email fails SPF or DKIM checks

Most email service providers (like ConvertKit, Flodesk, or Klaviyo) walk you through this step, but it’s still on you to actually connect your domain. If you’re sending emails from a custom domain without authentication, spam filters will side-eye you immediately, no matter how good your copy is.

2. Maintain a Strong Sender Reputation

Think of sender reputation like a credit score for your email address. Inbox providers track how trustworthy you are over time, based on how recipients interact with your emails.

To protect and improve your reputation:

Only email people who opted in (no purchased lists, ever)
Remove inactive subscribers (cold subscribers) regularly. People who never open your emails hurt your metrics
Send consistently, not in random bursts after long silences
Avoid sudden spikes in volume, especially on a new domain

If subscribers delete your emails without opening them, mark them as spam, or never engage, email providers interpret that as a sign your content isn’t wanted, and they’ll start routing future emails straight to spam.

3. Write Emails People Actually Want to Open

You can have perfect authentication and still land in the spam box if your emails don’t feel human. Engagement is one of the strongest deliverability signals. The more people open, read, reply to, or click your emails, the more inbox providers trust you.

To boost engagement:

Write clear, honest subject lines (not clickbait)
Keep your emails conversational and skimmable
Use plain text or simple formatting instead of heavy design
Ask readers to reply. Replies are gold for deliverability (and they help foster a community, which leads to better engagement and sales in the longrun)!
Focus on one main idea per email

Ironically, overly “salesy” emails trigger spam filters and turn readers off. The goal isn’t to avoid selling. It’s to make your emails feel like they came from a real person, not a marketing department.

4. Be Careful With Links, Images, and Formatting

Spam filters analyze how your email is built, not just what it says.

A few best practices:

Don’t overload emails with links (especially shortened or unfamiliar URLs)
Avoid image-only emails. Always include text!
Stick to one font size and color whenever possible
Make sure your HTML is clean and error-free
Always include a visible unsubscribe link

Messy formatting, broken code, or suspicious links can send even a well-written email straight to spam.

5. Warm Up New Domains and Email Addresses

If you’re sending from a new domain or email address, inbox providers don’t trust you yet, and they shouldn’t. You need to warm it up gradually.

Start by:

Sending to your most engaged subscribers first. I recommend always having a welcome series!
Prioritizing value-driven content over promotions

This helps establish positive engagement early, which sets the tone for long-term deliverability.

Email Spam Triggers to Avoid

Okay, now that we’ve covered the basics, let’s dig into what words and phrases you should avoid to prevent your emails from going to spam. Run through this list when writing, and you’ll have a much higher chance of actually landing in your readers’ inboxes!

1. Exaggerated Claims and Promises

#1
100% more
100% free
100% satisfied
Additional income
Be your own boss
Best price
Big bucks
Billion
Cash bonus
Cents on the dollar
Consolidate debt
Double your cash
Double your income
Earn extra cash
Earn money
Eliminate bad credit
Extra cash
Extra income
Expect to earn
Fast cash
Financial freedom
Free access
Free consultation
Free gift
Free hosting
Free info
Free investment
Free membership
Free money
Free preview
Free quote
Free trial
Full refund
Get out of debt
Get paid
Giveaway
Guaranteed
Increase sales
Increase traffic
Incredible deal
Lower rates
Lowest price
Make money
Million dollars
Miracle
Money back
Once in a lifetime
One time
Pennies a day
Potential earnings
Prize
Promise
Pure profit
Risk-free
Satisfaction guaranteed
Save big money
Save up to
Special promotion

2. Unnecessary Urgency and Pressure

Act now
Apply now
Become a member
Call now
Click below
Click here
Get it now
Do it today
Don’t delete
Exclusive deal
Get started now
Important information regarding
Information you requested
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
Will not believe your eyes
Winner
Winning
You are a winner
You have been selected

3. Words That Look Spammy or Unethical

Bulk email
Buy direct
Cancel at any time
Check or money order
Congratulations
Confidentiality
Cures
Dear friend
Direct email
Direct marketing
Hidden charges
Human growth hormone
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 interest
No investment
No obligation
No purchase necessary
No questions asked
No strings attached
Not junk
Notspam
Obligation
Passwords
Requires initial investment
Social security number
This isn’t a scam
This isn’t junk
This isn’t spam
Undisclosed
Unsecured credit
Unsecured debt
Unsolicited
Valium
Viagra
Vicodin
We hate spam
Weight loss
Xanax

4. Jargon or Legalese Words

Accept credit cards
Ad
All new
As seen on
Bargain
Beneficiary
Billing
Bonus
Cards accepted
Cash
Certified
Cheap
Claims
Clearance
Compare rates
Credit card offers
Deal
Debt
Discount
Fantastic
In accordance with laws
Income
Investment
Join millions
Lifetime
Loans
Luxury
Marketing solution
Message contains
Mortgage rates
Name brand
Offer
Online marketing
Opt in
Pre-approved
Quote
Rates
Refinance
Removal
Reserves the right
Score
Search engine
Sent in compliance
Subject to…
Terms and conditions
Trial
Unlimited
Warranty
Web traffic
Work from home

5. Crypto & Investing Triggers

Crypto
Cryptocurrency
Bitcoin
NFTs
Blockchain
Passive income
High yield
Guaranteed returns
Investment opportunity
Trading signals

6. Sweepstakes / Giveaway Language

Claim your prize
You’ve been chosen
Lucky winner
Selected winner
Act immediately
Redeem now

7. Personal Data & Security Flags

Verify your account
Confirm your identity
Account suspended
Login details
Update your information
Security alert
Unusual activity

8. Non-Word Spam Triggers (These Matter Just as Much)

Excessive punctuation (!!!, ???)
Repeated symbols ($$$, ###)
ALL CAPS subject lines or sentences
Subject lines that don’t match email content
Too many links (especially to different domains)
URL shorteners (bit.ly, tinyurl, etc.)
Image-heavy emails with very little text
Attachments (especially PDFs or ZIP files)
Broken or sloppy HTML
Emoji overload (especially 🚨💰🔥🎁 in subject lines)

NOTE: It’s important to note that modern spam filters don’t rely on single keywords alone. Authentication, sender reputation, engagement, and sending behavior now play a larger role than any individual word.

In Conclusion

Spam triggers can absolutely hurt your email performance, but they’re only one piece of the deliverability puzzle. While certain words and phrases can raise red flags, modern spam filters look at the full context of your emails, including authentication, sender reputation, engagement, and overall sending behavior.

The biggest takeaway? Focus less on trying to “outsmart” spam filters and more on writing emails your subscribers actually want to open, read, and respond to. When your audience engages with your content consistently, inbox providers take notice, and your emails are far more likely to land where they belong.

Use the spam trigger lists in this post as a guide, not a rulebook. Be intentional with your language, keep your formatting clean, send emails consistently, and always prioritize value over hype. Do that, and you’ll not only avoid the spam folder, but you’ll build a healthier, more profitable email list over time!

More Helpful Resources

Hi! I’m Shyanne.

I’ve been a content writer for 8 years now. I fell into this filed by accident after applying to a VA position from a nutritionist while in college.

Fast forward a few years later, and I had an English degree with a concentration in Creative Writing and minors in History and Nutrition, and a fledgling business.

Now, I help food bloggers, fitness experts, and health professionals with done-for-you blog writing and done-for-you email writing services!

Growing up, I always loved food and cooking, and writing was my first passion. Later, I discovered fitness and nutrition, and pursued personal training before really leaning into my writing career. Now, getting to marry all of my passions while helping others achieve their own goals truly feels like a dream.

I love all aspects of writing and am trained in SEO and copywriting. If you’re interested in hiring a content writer to handle your needs, I promise you’ll be in good hands!