Your email is getting flagged. You're not sure why. You've heard about "spam words" - phrases that trigger filters - but nobody gives you a straight list of what actually matters versus marketing myth.
Here's the reality: not all spam words are created equal. Some genuinely hurt deliverability. Others are repeated so often they've become meaningless advice. This post breaks down which words actually matter, why they matter, and what to use instead.
The Spam Words That Actually Damage Your Deliverability
Gmail, Outlook, and the major email providers use filters that scan for certain trigger phrases. When they appear too frequently, or in combination with other red flags, they tank your sender reputation. Here are the ones that consistently cause problems:
- "Limited time offer" / "Act now" / "Urgent" - These are the clearest signals of promotional email. If you use them in a cold email, you sound like you're selling to a list, not reaching out to a specific person. Spam filters weight these heavily.
- "FREE" (in all caps or multiple exclamation marks) - All-caps FREE is a classic spam signal. Lowercase "free" in context is fine. "Free consultation" reads differently than "FREE!!!"
- "Click here" / "Click below" - This language screams automated newsletter. In cold email, you want to be conversational. "Here's a case study I thought you'd find relevant" works. "Click here for our case study" doesn't.
- "Guarantee" / "Risk-free" - These words trigger skepticism filters because they're common in high-pressure sales. You don't need them in cold email.
- "No obligation" / "No credit card required" - Same as above. You're already reaching out cold - you don't need to promise there's no catch.
- "Unsubscribe here" - Wait. You need an unsubscribe link for CAN-SPAM compliance. We'll cover this in a second.
The pattern here: these words are industry-standard in marketing emails sent to purchased lists. Cold email works because it's different - it's person-to-person, not broadcast. The moment you sound like a newsletter, your reputation takes a hit.
The Words Everyone Warns About That Actually Don't Matter Much
You've probably heard you should avoid words like "opportunity", "success", "winner", "congratulations". Here's the truth: modern filters don't weight these heavily anymore. They were problem words in 2010. They're not now.
Why? Because these words appear in legitimate business emails too. Someone congratulating you on a promotion, a partner telling you about a real opportunity. The filters learned they're not reliable spam indicators.
That said, using 15 of them in one email is still dumb. It reads like spam. Just don't use them unnecessarily. There's no need to artificially avoid them either.
The Unsubscribe Link Problem
Here's where it gets tricky. Cold email laws require an unsubscribe mechanism. So you need to include something like:
Want to opt out of emails like this? Reply with "unsubscribe" and I'll remove you right away.
Or a standard unsubscribe footer. But if you add typical spam-y language around it - "Click here to unsubscribe immediately" or "Unsubscribe | Privacy Policy | Contact Us" in that classic footer format - you're signaling "this is a mass email."
The fix: keep it minimal and conversational. A single line at the bottom works fine. You don't need the links-in-rows format that broadcast emails use. For more on compliance without tanking deliverability, check out our guide on B2B email spam compliance.
What To Use Instead: The Replacement Language
Instead of relying on old spam-word lists, use language that shows this is a real, person-to-person outreach:
Hey [Name], I noticed [specific thing about their business]. We've helped similar companies in [industry] do [specific result]. Would be worth a quick call to see if it applies to you? [Your name]
Notice what's here: specificity, relevance, a clear ask, and nothing that reads like a template. That's the actual competitive advantage. Not avoiding words - just sounding like a human.
Here are replacements for the actual problematic phrases:
- Instead of "Act now" - "Let me know if this interests you" or just ask directly
- Instead of "Limited time" - Don't mention time constraints at all. You're reaching out personally, not running a flash sale
- Instead of "Click here" - Use the actual link in context: "Here's a case study from a similar client" (hyperlink the whole phrase)
- Instead of "Guarantee" - Just describe what you actually did: "We got them from X to Y in 90 days"
- Instead of "Risk-free" - Don't mention risk at all. Focus on the value you've delivered elsewhere
The Real Deliverability Problem Isn't Words - It's Pattern
Here's what actually tanks cold email deliverability: sending the same template to 500 people. Using the exact same subject line. Same opening line. Same call to action.
Spam filters have gotten smart enough to detect patterns. If your email could apply to literally anyone in an industry, it looks like a broadcast. Even if it has zero technical spam words.
So the actual fix isn't scanning your copy for forbidden terms. It's personalization that goes beyond just adding someone's name. Mention something specific - their company, a recent announcement, an industry challenge you know they face. That's what makes filters view you as real outreach instead of spam.
You also want to make sure your infrastructure is set up correctly - your domain reputation, your sending patterns, your email authentication. Those matter way more than any individual word choice. For a deeper dive, check out our post on how to keep cold emails out of the spam folder.
Quick Audit: Is Your Email at Risk?
Run through this checklist:
- Does this email use more than 2 of the high-risk words from the first section? Flag it.
- Does it sound like it could be sent to 100 people unchanged? That's a problem regardless of word choice.
- Are you using all caps anywhere except the start of sentences? Change it.
- Do you have 5+ exclamation marks? Cut it to 1, maybe 2.
- Does your footer look like a newsletter (links in rows, privacy policy, multiple contact options)? Simplify it.
If you're checking 3+ boxes, rewrite it. If you're checking 0-1, you're probably fine on this front.
Where This Gets Hard at Scale
Knowing which words matter is one thing. Actually building a cold email campaign where every email avoids these pitfalls, maintains personalization, stays consistent with your brand voice, and hits your specific metrics - that's different.
You need to write copy that feels conversational instead of promotional, set up your email infrastructure correctly, make sure your personalization is genuine, and then actually monitor what's working. Most agencies either nail the copy or the infrastructure, rarely both. That's the gap that kills most cold email operations before they scale.