Why are articles listing spam words to avoid considered bad advice?
Matthew Whittaker
Co-founder & CTO, Suped
Published 13 Jul 2025
Updated 16 Aug 2025
6 min read
For years, email marketers have diligently consulted lists of 'spam words' to avoid, believing these terms were direct triggers for spam filters. Articles titled '300+ Spam Words to Avoid' or similar have proliferated, guiding senders to meticulously scrub their copy of words like 'free', 'discount', or 'urgent'. This advice, while well-intentioned, is largely outdated and can even be detrimental to your email deliverability efforts.
The truth is, modern anti-spam filters are far more sophisticated than simple keyword detectors. They operate on complex algorithms that analyze a multitude of factors to determine whether an email belongs in the inbox or the spam folder. Focusing solely on a list of forbidden words distracts from the real issues affecting your email deliverability (or inbox placement, if you prefer that term).
My goal here is to explain why these lists are considered bad advice and redirect your focus to what truly matters in email deliverability.
The evolution of spam filtering
In the early days of email, spam filters were indeed quite basic, often relying on rudimentary keyword matching. If your email contained a word commonly associated with unsolicited bulk mail, it was likely flagged. This led to the widespread belief that avoiding a 'blacklist' (or blocklist) of specific words was the key to successful email delivery. However, spammers quickly adapted, rendering these simple keyword filters ineffective. Mailbox providers had to evolve.
Today, spam filters function more like advanced threat intelligence systems. They don't just look at individual words; they evaluate the sender's reputation, email authentication, content context, recipient engagement, and even the email's structure. A single 'spam word' used innocuously is highly unlikely to trigger a filter if all other signals indicate a legitimate sender. For example, a reputable e-commerce store sending an email about a 'free shipping' offer will likely land in the inbox, whereas a suspicious sender using the same phrase might be blocked.
Old spam filters (keyword-focused)
Content analysis: Primarily based on specific trigger words and phrases in the subject line or body.
Limited context: Less consideration for the overall context or sender legitimacy.
Static lists: Relied on static lists of 'forbidden' terms, easily circumvented by spammers.
Engagement metrics: Analyzes user interaction (opens, clicks, replies, complaints) as key signals.
Advanced content analysis: Uses machine learning to understand intent, language patterns, and content relevance, not just individual words.
Mailbox providers like Google (Gmail) and Yahoo (formerly Oath) continuously refine their algorithms to combat spam effectively. Their systems are designed to identify malicious intent and deceptive practices, not just the presence of certain words. Focusing on a list of spam words can be a huge misdirection. If you're wondering how anti-spam filters work, they are constantly updated and use a variety of signals.
Why keyword lists are misleading and potentially harmful
The primary issue with spam word lists is that they foster a false sense of security while ignoring the true complexities of email deliverability. A marketer might obsess over avoiding 'free' but completely overlook critical elements like proper DMARC configuration, a poor sender reputation, or a non-existent list cleaning strategy. These are the factors that genuinely move the needle.
Moreover, attempting to avoid common, legitimate words can make your email copy sound unnatural, forced, or even suspicious. If your message sounds like it's trying to evade detection, it might inadvertently raise red flags with more sophisticated filters. Authenticity and clear communication are far more valuable than linguistic gymnastics to avoid a perceived 'trigger word'.
The trap of over-censoring
Over-reliance on outdated spam word lists can lead to self-censorship that harms your marketing efforts. If you're a legitimate business, you shouldn't have to avoid terms like 'discount', 'sale', or 'exclusive offer' if they accurately describe your promotion. Your focus should be on building a positive sender reputation and maintaining a healthy email ecosystem, rather than getting caught up in a word game.
Many of these lists include words that are part of everyday language or essential for marketing communication. Imagine avoiding 'here' or 'subscribe' in an email. It becomes clear how impractical and damaging such rigid adherence can be. This misguided approach can result in generic, ineffective emails that fail to resonate with your audience, regardless of whether they hit the inbox.
What truly impacts your email deliverability
Instead of chasing mythical spam words, invest your energy in the factors that truly determine whether your emails land in the inbox. These are the cornerstones of strong email deliverability:
Factor
Description
Impact on Deliverability
Sender reputation
Mailbox providers assign a reputation score to your sending IP and domain based on past sending behavior, user complaints, and blocklist (or blacklist) listings.
High reputation is paramount for inbox placement. Low reputation leads to spam folder or rejection.
Email authentication
Implementing SPF, DKIM, and DMARC verifies your emails are legitimate and haven't been tampered with.
Essential for proving your identity and protecting your domain from phishing and spoofing. Without it, emails are often flagged.
Recipient engagement
Opens, clicks, replies, and emails moved to the inbox signal positive engagement. High complaint rates or low engagement are red flags.
Strong engagement tells mailbox providers your content is valued by recipients, improving deliverability.
List hygiene
Regularly removing inactive subscribers, invalid addresses, and spam traps from your list.
A clean list reduces bounces and complaints, protecting your sender reputation and avoiding blocklists.
Content quality & relevance
Beyond individual words, filters assess the overall message for spammy characteristics like excessive images, broken links, or misleading claims.
Well-written, relevant content that provides value to the recipient is less likely to be flagged.
These are the true levers of email deliverability. A robust email program prioritizes building and maintaining a strong sender reputation through consistent authentication, engaging content, and diligent list management. You can learn more about how your email address might end up on a blacklist in our other resources.
It's a common misconception that certain naming choices in an envelope domain or a generic email address can trigger spam filters directly. While these aren't 'spam words' in the traditional sense, they relate to overall sender identity. The reality is that the broader context of your sending practices and domain trust matters much more than isolated elements.
Views from the trenches
Best practices
Focus on building a strong sender reputation through consistent positive engagement metrics.
Implement and monitor email authentication protocols like SPF, DKIM, and DMARC for legitimacy.
Maintain meticulous list hygiene by regularly removing unengaged or invalid email addresses.
Prioritize sending relevant, valuable content that encourages positive recipient interaction.
Test your email campaigns thoroughly, looking at delivery rates and inbox placement across major providers.
Common pitfalls
Over-reliance on outdated spam word lists, diverting attention from critical deliverability factors.
Neglecting sender reputation monitoring, leading to undetected issues with email delivery.
Failing to authenticate emails properly, causing messages to be flagged as suspicious or spoofed.
Sending emails to unengaged lists, which increases bounce rates and spam complaints.
Producing generic or overly promotional content that offers little value to the recipient.
Expert tips
Modern spam filters use sophisticated AI and machine learning, making static keyword lists irrelevant.
Sender reputation, engagement, and authentication are the primary factors influencing inbox placement.
Legitimate businesses should not censor common marketing terms if they are used authentically.
Monitor your deliverability metrics actively to identify and address underlying issues, rather than just content.
Email deliverability is a holistic challenge, requiring attention to multiple technical and content-related aspects.
Expert view
Expert from Email Geeks says that articles promoting extensive lists of spam words are outdated and provide poor advice for email deliverability.
March 24, 2023 - Email Geeks
Marketer view
Marketer from Email Geeks asked why these spam word lists are considered bad advice, indicating a common point of confusion.
In conclusion, while avoiding overtly spammy language is always wise, fixating on exhaustive lists of 'spam words' is a relic of email marketing's past. The landscape of email deliverability has evolved dramatically, placing emphasis on sender reputation, robust authentication, and genuine recipient engagement. If you are struggling with emails going to spam, the solution lies in a holistic approach, not in a list of words to avoid.
True email deliverability success comes from understanding the nuanced way mailbox providers assess your sending practices. Focus on maintaining a healthy sender reputation, ensuring your email authentication (like DMARC) is correctly configured, and consistently delivering valuable content to an engaged audience. These are the foundations upon which consistent inbox placement is built, not merely avoiding a few 'bad' words.
By shifting your strategy away from outdated myths and towards modern best practices, you'll be far better equipped to navigate the complexities of email deliverability and consistently reach your audience's inbox. This will also help you avoid being caught on an email blocklist or blacklist.
