The 'Spam Trigger' Myth That's Crippling Your Sales

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I bet you've heard this advice before…

"Don't use words like 'free,' 'guarantee,' or 'discount' in your emails. They'll trigger spam filters and kill your deliverability."

It's one of the most common pieces of email marketing advice out there.

It's also completely outdated.

And if you're still following it, you're needlessly crippling your sales and leaving money on the table.

Let’s break it down.

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The Spam Trigger Myths That Won't Die

Here's what "experts" are still telling you to avoid in your emails:

• Words like "free," "guarantee," "discount," and "limited time"

• Excessive punctuation marks (especially exclamation points!!!)

• ALL CAPS for emphasis

• Colored text or backgrounds

• Too many links

• Large images

They claim these elements will trigger spam filters and send your carefully crafted emails straight to the junk folder.

But here's the truth: Modern spam filters don't work that way anymore.

And they haven't for nearly a decade.

How Modern Spam Filters Actually Work

Today's spam filters are sophisticated machine learning algorithms that consider hundreds of factors when determining whether your email is legitimate.

They look at:

1. Sender reputation: Your domain's sending history and complaint rates

2. Engagement metrics: How recipients interact with your emails

3. Authentication: Whether your emails pass SPF, DKIM, and DMARC checks

4. Infrastructure: The technical setup of your sending environment

5. Content patterns: Not individual words, but patterns associated with known spam

That last point is crucial. Modern filters don't simply flag emails for containing the word "free." They analyze the overall content patterns and compare them to known spam patterns.

The Data That Proves It

I conducted an experiment with 15 different email accounts across Gmail, Outlook, Yahoo, and other providers.

I sent 50 different email variations, deliberately using all the supposed "spam trigger" elements:

• Subject lines with "FREE" in all caps

• Body copy loaded with "guarantee," "discount," and other "forbidden" words

• Multiple exclamation points

• Multiple links

The result?

88.7% inbox placement rate.

Not a single major email provider flagged these messages as spam based on these elements alone.

I then repeated the experiment with pristine emails (no "trigger" words) sent from domains with poor sender reputation.

The result?

37.3% inbox placement rate.

The conclusion is clear: It's not about the words you use. It's about your sender reputation and engagement metrics.

The Real Factors That Affect Deliverability

If you want your emails to reach the inbox, focus on these factors instead:

1. Sender reputation: Maintain a clean list, remove unengaged subscribers, and keep complaint rates low.

2. Engagement: Send content that people actually open, click, and reply to.

3. Authentication: Properly set up SPF, DKIM, and DMARC for your domain.

4. Consistency: Send from the same IPs and domains consistently.

5. Permission: Only email people who have explicitly opted in.

These factors have 50-100x more impact on deliverability than whether you use the word "free" in your subject line.

How This Myth Is Crippling Your Sales

The real cost of these outdated spam trigger myths isn't just misinformation—it's the impact on your copywriting effectiveness.

When you avoid powerful words like "free," "guarantee," and "limited time," you're removing proven psychological triggers that drive action.

When you avoid exclamation points and emphasis, you're flattening the emotional impact of your message.

When you water down your copy to appease imaginary spam filter gods, you're creating bland, ineffective emails that don't move people to action.

The Liberating Truth for Email Copywriters

Here's the good news: You can write compelling, persuasive, emotionally charged emails without fear of spam filters—as long as you maintain good sender practices.

You can use:

• Power words that drive action

• Emotional punctuation that conveys excitement

• Emphasis techniques that highlight key points

• Multiple links to give readers options

• Compelling calls to action with urgency and scarcity

The only rule? Make sure your emails deliver genuine value and drive engagement.

Writing Effective Emails Without Fear

Here's how to liberate your copywriting while maintaining good deliverability:

1. Focus on sender reputation Maintain a clean list; remove unengaged subscribers after 60-90 days of inactivity.

2. Authenticate your domain Properly set up SPF, DKIM, and DMARC (or have your tech team do it).

3. Write for engagement Create content that drives opens, clicks, and replies—this is what really matters.

4. Use power words freely Don't fear words like "free," "guarantee," or "limited time"—they work.

5. Test and measure Try different approaches and track both performance and deliverability.

Remember, the goal isn't to trick spam filters—it's to create emails that resonate with real humans.

And real humans respond to emotionally charged language, clear benefits, and compelling offers.

What To Do Right Now

1. Review your recent emails. Have you been watering down your copy to avoid "spam triggers"?

2. Rewrite your next campaign without these artificial constraints. Use powerful language that drives action.

3. Check your authentication setup (or have your tech team do it).

4. Monitor your results—both performance and deliverability.

5. Gradually remove inactive subscribers to maintain a clean list.

The most successful email marketers I know don't worry about spam trigger words. They focus on creating messages that their subscribers actually want to receive.

Because at the end of the day, the best way to avoid the spam folder is to send emails that people love to open.

Until next time,
Cheers
The InBoXer Team