Are spam trigger word lists still relevant for email deliverability?

Summary

The consensus across expert and marketer opinions, alongside documentation from various sources (Google, Microsoft, SpamAssassin, RFC), is that while spam trigger word lists are not the *primary* determinant for email deliverability, they are still somewhat relevant. Modern spam filters rely on sophisticated algorithms, considering context, sender reputation, user engagement, and authentication (SPF, DKIM, DMARC). Bayesian filtering does not rely on specific words. While avoiding overtly spammy language, aggressive sales tactics, misleading subject lines, excessive capitalization, and multiple exclamation points can still raise red flags and trigger spam filters or user’s ‘spam radar’, some organizations may implement custom content filters using these word lists. Focusing on building a healthy email program, permission-based lists, relevant content, good sender reputation and consistent sending habits are paramount. Testing common myths, like 'free' being a trigger word, is also recommended. Using certain emojis or multiple colours and fonts may negatively affect deliverability.

Key findings

  • Context & Reputation are Key: Email context, sender reputation, user engagement, and proper authentication (SPF, DKIM, DMARC) outweigh the impact of individual spam trigger words.
  • Holistic Analysis: Spam filters analyze overall content features and context, relying on scoring systems based on multiple factors, not just specific words.
  • Aggressive Tactics Penalized: Overly salesy or aggressive language, misleading subject lines, excessive capitalization, multiple exclamation points, and outdated tactics are still flagged.
  • Custom Filters Possible: Some organizations use custom content filters, though deliverability experts focus on global filters instead.
  • Testing Recommended: Assumptions, like 'free' being a trigger, should be tested instead of blindly followed.

Key considerations

  • Prioritize Reputation & Engagement: Build and maintain a positive sender reputation and foster genuine user engagement through relevant and valuable content.
  • Implement Robust Authentication: Ensure proper email authentication (SPF, DKIM, DMARC) to verify sender identity and establish trust.
  • Avoid Outdated Tactics: Be mindful of language, content, and email design, avoiding outdated spam tactics, excessive formatting, and misleading claims.
  • Monitor & Adapt: Regularly monitor email performance and adapt practices based on feedback, testing, and evolving spam filtering techniques.
  • Focus on Value: Provide value to recipients and avoid practices that might appear deceptive or manipulative.

What email marketers say
11Marketer opinions

While the consensus is that spam trigger word lists are not the *primary* determinant of email deliverability, they still hold some relevance. Modern spam filters prioritize factors like sender reputation, authentication (SPF, DKIM, DMARC), and engagement. However, using overtly spammy language, aggressive sales tactics, misleading subject lines, excessive capitalization, and multiple exclamation points can still raise red flags and potentially trigger spam filters or users' 'spam radar'. Some organizations even implement custom content filters based on these lists. Therefore, while focusing on building a healthy email program with valuable, relevant content and a good sender reputation is paramount, it's still prudent to be mindful of language and avoid outdated spam tactics.

Key opinions

  • Reputation & Authentication: Sender reputation, email authentication (SPF, DKIM, DMARC) and user engagement are now the most important factors for deliverability.
  • Sophisticated Filters: Modern spam filters are sophisticated and consider a wide range of factors beyond just trigger words, including content relevance.
  • Aggressive Language: Overly salesy or aggressive language, misleading subject lines, excessive capitalization, and multiple exclamation points can raise red flags.
  • Custom Filters: Organizations may use custom content filters based on spam trigger word lists.
  • Still Relevant: While not the primary factor, spam trigger words can still contribute to spam filtering.

Key considerations

  • Prioritize Building a Healthy Program: Focus on building a healthy email program with permission-based lists, relevant content, and a good sender reputation.
  • Avoid Outdated Tactics: Be mindful of language and avoid outdated spam tactics like excessive capitalization, multiple exclamation points, and overly salesy phrasing.
  • Review Content: Review content for potentially problematic phrases, but don't obsess over rigid lists of trigger words.
  • Email Authentication: Check you have SPF, DKIM, and DMARC setup correctly.
  • Be Transparent: Avoid subject lines that could be considered misleading.
Marketer view

Email marketer from Constant Contact states that trigger words aren't as critical as they used to be, and that focusing on clear, concise messaging and delivering value is more important. They advise avoiding excessive capitalization, multiple exclamation points, and other outdated spam tactics.

August 2022 - Constant Contact Blog
Marketer view

Email marketer from an Email Marketing Forum responds by suggesting that while trigger words aren't the biggest issue, overly salesy or aggressive language can still raise red flags. ForumUser42 explains that focusing on providing value and building trust with your audience is more effective than worrying about a list of specific words.

October 2023 - Email Marketing Forum
Marketer view

Email marketer from Moosend states that spam words can still trigger spam filters, but suggests that deliverability is impacted most by engagement and sender reputation.

December 2022 - Moosend
Marketer view

Email marketer from Mailchimp shares that while avoiding overtly spammy language is helpful, modern spam filters are more intelligent and focus on factors like authentication, engagement, and sender reputation. They suggest focusing on building a healthy list and sending relevant content.

June 2024 - Mailchimp
Marketer view

Email marketer from Omnisend notes that spam trigger words still matter, but are not the only thing that matters. They also say that avoiding certain words can prevent triggering peoples' 'spam radar'.

July 2022 - Omnisend
Marketer view

Email marketer from Hubspot warns against using caps and lots of exclamation points in email. They also suggest reviewing content for known spam words.

November 2023 - HubSpot
Marketer view

Email marketer from Litmus shares that modern spam filters are sophisticated and consider a wide range of factors beyond just trigger words. Litmus explains that authentication, sender reputation, engagement, and content relevance play a larger role in deliverability. They advise focusing on building a healthy email program.

April 2022 - Litmus
Marketer view

Email marketer from ZeroBounce says that using spam words is not the most important thing to look out for, but suggests that senders should still ensure that they are not using misleading subject lines.

November 2022 - ZeroBounce
Marketer view

Email marketer from Sendinblue responds that while spam trigger words aren't the primary factor, they can still contribute to spam filtering. They advise avoiding common spam phrases, focusing on permission-based lists, and maintaining good sender reputation.

February 2024 - Sendinblue
Marketer view

Email marketer from Email Geeks shares that organizations may implement custom content filters with spam trigger words, often copied from online lists, to block specific types of emails.

August 2022 - Email Geeks
Marketer view

Email marketer from Reddit suggests that trigger words are less important now, saying that sender reputation, authentication (SPF, DKIM, DMARC), and engagement are the most important factors. Bad reputation and non-authenticated emails will get flagged regardless of content.

October 2024 - Reddit

What the experts say
7Expert opinions

Experts largely agree that spam trigger word lists are not the primary factor determining email deliverability. SpamAssassin rules focus on content features, not just words, and Bayesian filtering doesn't rely on specific words. While some organizations might use custom word filters, deliverability experts focus on broader issues like authentication, sending wanted email, engagement, consistent sending volume, and low complaint rates. The idea that single words like 'free' act as spam triggers is considered a myth; experts encourage testing such claims.

Key opinions

  • Content Features > Words: SpamAssassin and other filters analyze overall content features and context, not just individual words.
  • Bayesian Filtering: Bayesian filtering, a common spam filtering technique, does not operate on specific words.
  • Custom Filters Exist: Organizations may implement custom content filters, but these are outside the scope of global deliverability strategies.
  • Focus on Core Deliverability: Authentication, engagement, volume, and complaint rates are the most critical factors for deliverability.
  • 'Free' Myth: The idea that the word 'free' automatically triggers spam filters is likely a myth.

Key considerations

  • Test Assumptions: Test deliverability assumptions instead of relying on outdated lists.
  • Prioritize Authentication: Ensure proper email authentication (SPF, DKIM, DMARC).
  • Encourage Engagement: Focus on sending wanted email to encourage recipient engagement.
  • Monitor Sending: Maintain consistent sending volume and monitor complaint rates.
  • Global vs. Local: Understand that deliverability expertise focuses on global filters, not individual organizational decisions.
Expert view

Expert from Spam Resource explains that focusing on spam trigger words is often a waste of time. Al Iverson suggests deliverability professionals should instead focus on authenticating email properly, sending wanted email, sending mail people engage with, sending the same volume every day, and keeping complaint rates low.

June 2024 - Spam Resource
Expert view

Expert from Word to the Wise shares that the idea that 'free' is a spam trigger is a myth. Laura Atkins suggests that people should test the word 'free' and see if it impacts deliverability.

December 2024 - Word to the Wise
Expert view

Expert from Email Geeks explains that most SpamAssassin rules aren't about specific words, but about distinctive features of content. Word-related rules often contribute to broader metarules analyzing multiple data points.

October 2021 - Email Geeks
Expert view

Expert from Email Geeks explains that while organizations can choose to implement their own content filters, deliverability experts primarily focus on the global filters set by outsourced providers, as individual organizational choices are beyond their control.

February 2024 - Email Geeks
Expert view

Expert from Email Geeks shares that some spam word lists come from actual spammers. She mentions the advice to "never use FREE in the subject line" has been around since the late 90s.

December 2024 - Email Geeks
Expert view

Expert from Email Geeks points out that using certain emojis in the 'from' address can negatively impact deliverability with some providers, though emojis are not words.

October 2022 - Email Geeks
Expert view

Expert from Email Geeks clarifies that Bayesian filtering is not based on specific words.

September 2024 - Email Geeks

What the documentation says
4Technical articles

Technical documentation from Google, Microsoft, SpamAssassin, and RFC indicates that while specific words and phrases *can* contribute to an email being flagged as spam, modern spam filters rely on a complex scoring system that considers numerous factors. Key aspects include sender reputation, content analysis, user feedback, email authentication, sending history, and overall context. Focusing solely on avoiding 'spam trigger words' is an oversimplification, as the combination of factors and the overall email presentation determine whether a message lands in the inbox or the junk folder. Multiple colours and fonts could also trigger spam alerts.

Key findings

  • Holistic Scoring: Spam filters use a scoring system based on multiple factors, not just specific words.
  • Context Matters: The overall context of the email and its content are crucial.
  • Sender Reputation: Sender reputation and sending history significantly influence deliverability.
  • Authentication is Key: Proper email authentication (SPF, DKIM, DMARC) is essential.
  • Email Design: Email design, like using multiple colours or fonts, can affect email deliverability.

Key considerations

  • Prioritize Reputation: Focus on building and maintaining a positive sender reputation.
  • Authenticate Your Email: Ensure proper email authentication to verify sender identity.
  • Monitor Feedback: Pay attention to user feedback and adjust sending practices accordingly.
  • Improve Content: Improve content quality and relevance to increase engagement.
  • Email Design: Use a simple email design.
Technical article

Documentation from Microsoft Support explains that their junk email filters consider many factors, including sender reputation, content analysis, and user feedback. It notes that while certain phrases can contribute to a message being flagged, it's the combination of factors that determines whether an email goes to the junk folder. Microsoft recommends ensuring proper authentication and a good sending history.

August 2022 - Microsoft Support
Technical article

Documentation from SpamAssassin Wiki explains that SpamAssassin uses a scoring system where rules are assigned weights. While some rules may look for specific words, they are often part of a larger set of tests, and the overall score determines whether a message is considered spam. They mention that focusing solely on avoiding certain words is an oversimplification.

July 2022 - SpamAssassin Wiki
Technical article

Documentation from Google Workspace Admin Help explains that Google uses sophisticated algorithms to identify spam, and while certain words can contribute to a message being flagged, it's the overall context and sender reputation that are most important.

August 2021 - Google Workspace Admin Help
Technical article

Documentation from RFC, which outlines rules about email, shares that certain phrases and content can trigger spam alerts. Using multiple colours and fonts can have a negative impact.

January 2024 - RFC-822