Are spam trigger word lists accurate and should I be concerned about them?
Michael Ko
Co-founder & CEO, Suped
Published 10 Jun 2025
Updated 19 Aug 2025
6 min read
The idea that a simple list of specific "spam trigger words" can dictate whether your emails land in the inbox or the spam folder is a persistent myth in email marketing. Many marketers, both new and experienced, often come across articles claiming to have definitive lists of hundreds of words to avoid, believing that steering clear of these terms will guarantee deliverability.
I often hear questions about the accuracy of these lists and the extent to which they should concern email senders. The truth is, modern email spam filters are far more sophisticated than they once were. While certain words might have historically been associated with spam, relying solely on keyword avoidance is an outdated and largely ineffective strategy.
The evolution of spam filtering
Early spam filters primarily operated on a rudimentary keyword-matching system. If an email contained a high density of words like "Viagra," "free," or "earn money fast," it was likely to be flagged. This led to the creation of extensive (and often comically long) lists of words that senders were advised to avoid at all costs.
However, email filtering technology has evolved significantly. Today's inbox providers like Google and Microsoft employ advanced algorithms that analyze hundreds of variables beyond just individual words. These systems use artificial intelligence and machine learning to assess the overall context, sender reputation, engagement signals, and technical authentication.
This shift means that a single word, even one historically associated with spam, is unlikely to trigger a filter on its own. Instead, it's about the bigger picture of your sending behavior and the content of your email. The days of simply avoiding certain words to guarantee deliverability are long gone. For more on this, consider reading about whether spam trigger words are still relevant for deliverability.
Why static lists are misleading
The main problem with static spam word lists is that they completely miss the nuance of modern filtering. A word like "free" isn't inherently spammy if used legitimately, such as in free shipping or free trial. It's the context, sender reputation, and overall engagement that determine its impact, not just its presence.
Old spam filter logic
Keyword-centric: Heavy reliance on predefined lists of suspicious words and phrases.
Simple scoring: Each flagged word contributed a set score, leading to a cumulative spam score.
High false positives: Legitimate emails often caught due to innocent use of trigger words.
Modern spam filter logic
Holistic analysis: Contextual understanding of content, sender behavior, and engagement.
Reputation-driven: Sender IP and domain reputation are primary factors for filtering.
User interaction focus: Opens, clicks, replies, and spam complaints heavily influence inbox placement.
The idea that simply avoiding a set number of words will solve deliverability issues is, frankly, misguided. As Matthew Vernhout of Spam Resource aptly puts it, you could miss out on using perfectly legitimate words, or even worse, focus on a non-issue while actual problems, like a poor sender reputation (blacklist or blocklist listings), go unaddressed. You can also explore why articles listing spam words are bad advice.
It's far more productive to focus on delivering value to your subscribers. This means writing engaging content that your audience wants to receive, rather than obsessing over a list of words that might or might not be considered spammy. In fact, focusing on avoiding these words can make your emails sound unnatural and stiff, which ironically might reduce engagement and lead to worse deliverability.
What truly impacts deliverability
Instead of worrying about specific words, shift your focus to the factors that truly impact whether your emails reach the inbox. These include your sender reputation, email authentication, and subscriber engagement.
Key deliverability factors
Sender reputation: This is paramount. It’s built on consistent sending volume, low bounce rates, minimal spam complaints, and adherence to email best practices. High spam complaints, for example, can lead to your IP or domain being put on a blocklist (or blacklist), significantly harming your deliverability. Learn what happens when your domain is on a blocklist.
Email authentication: Implementing SPF, DKIM, and DMARC is crucial for proving your emails are legitimate and not forged. These protocols help prevent phishing and spoofing, which in turn improves your standing with inbox providers. A simple guide to DMARC, SPF, and DKIM can help you set these up.
Subscriber engagement: High open rates, click-through rates, and low unsubscribe rates signal to inbox providers that your emails are valued by recipients. This positive engagement greatly boosts your deliverability.
List hygiene: Regularly cleaning your email list to remove inactive or invalid addresses prevents bounces and spam trap hits (which can lead to blacklist or blocklist listings). Understanding how spam trap hits are a concern is important.
Focusing on these core elements will yield far better results than endlessly scrutinizing your email copy for spam words. Good email deliverability is about building trust with inbox providers and your audience, not about playing a guessing game with vocabulary.
For example, if you're writing about a financial product, terms like "loan" or "investment" are essential. If your sender reputation is good and your emails are authenticated, these words won't trigger spam filters on their own. However, if your sending practices are poor and you have a history of spam complaints, even innocuous words could contribute to a negative score.
Moving beyond the myth
To move beyond the myth of spam trigger word lists, I recommend embracing a comprehensive approach to email deliverability. Think about your email program holistically, from technical setup to content strategy and audience management.
Prioritize building and maintaining a strong sender reputation. This means sending only to engaged subscribers, managing your list actively, and ensuring your email authentication records (SPF, DKIM, DMARC) are correctly configured. A robust authentication setup tells inbox providers you are a legitimate sender.
Focus on creating compelling and relevant content that your subscribers want to receive and engage with. When recipients consistently open, click, and reply to your emails, it sends strong positive signals to spam filters. This positive engagement is far more impactful than trying to outsmart algorithms by avoiding arbitrary words.
Ultimately, your goal should be to foster a positive relationship with your subscribers and mailbox providers. This proactive approach, centered on trust and value, will ensure your emails consistently reach the inbox, allowing you to use the words necessary to communicate effectively.
Views from the trenches
Best practices
Focus on building a strong sender reputation rather than fixating on individual 'spam words.'
Implement SPF, DKIM, and DMARC to authenticate your emails, signaling legitimacy to inbox providers.
Regularly clean your email lists to remove inactive or invalid addresses and reduce bounce rates.
Prioritize creating valuable content that encourages positive subscriber engagement.
Monitor your deliverability metrics, such as open rates, click-through rates, and complaint rates.
Common pitfalls
Over-optimizing email copy to avoid perceived 'spam words,' making the content sound unnatural.
Neglecting sender reputation and technical authentication in favor of content changes.
Sending emails to unengaged or outdated lists, leading to high bounce and complaint rates.
Believing that avoiding a specific list of words guarantees inbox placement without addressing other factors.
Using misleading subject lines or deceptive practices that trick filters or recipients.
Expert tips
Your email deliverability is more about how your recipients engage with your emails than the specific words you use.
Modern spam filters consider the full context of an email, including sender history, links, and formatting, not just keywords.
An email's journey to the inbox is determined by a complex interplay of factors; focusing on one aspect in isolation is inefficient.
The best way to avoid the spam folder is to send valuable, requested content from a well-maintained sending infrastructure.
Don't let outdated advice on 'spam words' distract you from truly impactful deliverability strategies.
Expert view
An expert from Email Geeks says those extensive lists of spam words often look like a dump from old Spam Assassin rules. They might contribute to a spam score, but unless you use a vast number of them simultaneously, they are unlikely to be the sole cause of deliverability issues. It also means legitimate terms, like “medium” for a pizza order, would be unnecessarily flagged.
2023-03-02 - Email Geeks
Marketer view
A marketer from Email Geeks says many people still haven't received the memo that there's no such thing as a definitive list of spam words that will automatically land you in the junk folder.
2023-03-02 - Email Geeks
Embracing a holistic approach to email deliverability
The long, static lists of spam trigger words that once proliferated online are largely inaccurate and irrelevant for modern email deliverability. While they might have had some utility in the past, today’s advanced spam filters look far beyond simple keyword matching.
Your concern should not be focused on meticulously avoiding specific words, but rather on fostering a healthy sender reputation, ensuring proper email authentication (SPF, DKIM, DMARC), and consistently delivering valuable content that engages your audience. These are the true drivers of inbox placement.
By concentrating on these fundamental aspects of email hygiene and strategy, you can confidently craft your messages without fear that an innocent word will unfairly land you in the spam folder.
