Summary
Email deliverability is a complex arena where the role of specific keywords, while significant, is part of a larger, more sophisticated filtering process. While modern spam filters, often powered by machine learning, primarily weigh factors like sender reputation, engagement, and the overall context of an email, numerous experts and documentation confirm that certain 'spam trigger words' and phrases still contribute to an email's overall spam score. Terms related to scams, excessive urgency, or overly aggressive sales tactics, especially when combined with other red flags like poor formatting or suspicious links, can increase the likelihood of an email being flagged and routed to the spam folder. Regarding unsubscribe rates, it is crucial to understand that these are fundamentally recipient-driven actions, not direct consequences of spam filter decisions. Spam filters do not automatically unsubscribe users. However, a consistent failure to reach the inbox due to spam filtering- a process influenced by problematic keywords- can lead subscribers to perceive a lack of communication or relevance. This indirect effect may result in higher unsubscribe rates, as users might opt out if they are not receiving expected content or if their inbox is being cluttered by unwanted mail. User experience, content relevance, and the initial acquisition process are the primary drivers of unsubscribes.
Key findings
- Keywords Contribute to Spam Score: While not the sole factor, specific keywords and phrases still contribute to an email's 'spam score' within sophisticated filtering algorithms. This is particularly true when they appear alongside other indicators of low quality or suspicious content.
- Filters are Sophisticated: Modern spam filters are highly advanced, employing machine learning, sender reputation analysis, and comprehensive content parsing. They do not rely on simple keyword blacklists; instead, they evaluate the entire email's context, structure, and sender behavior.
- Unsubscribes are Recipient Actions: Spam filters do not directly unsubscribe users. Unsubscribe actions are conscious choices made by recipients, driven by factors like their perceived value of the content, relevance, or overall user experience.
- Indirect Impact on Unsubscribes: If emails consistently land in spam folders due to filtering mechanisms- to which problematic keywords can contribute- recipients may never see the messages. This lack of receipt can indirectly lead to higher unsubscribe rates as users disengage or perceive that communications have stopped.
Key considerations
- Prioritize Overall Quality: Focus on maintaining a strong sender reputation and adhering to comprehensive email best practices, as these factors are paramount for deliverability. While keywords play a role, they are one piece of a larger, complex puzzle that includes engagement, authentication, and content relevance.
- Cautiously Use Trigger Words: Exercise caution with words and phrases commonly associated with scams, excessive urgency, or aggressive sales tactics, especially in subject lines. While modern filters are sophisticated, these terms can still contribute to an email's spam score, particularly when combined with other negative signals.
- Monitor Deliverability & Engagement: Regularly track your email deliverability rates and subscriber engagement metrics. A high unsubscribe rate often indicates issues beyond just spam filters, such as misaligned user expectations or irrelevant content, which can be exacerbated if emails are not reaching the inbox.
- Understand Unsubscribe Drivers: Recognize that unsubscribes are typically user-initiated actions. Analyze your acquisition process, content strategy, and recipient satisfaction to address the root causes of unsubscribes, rather than solely attributing them to spam filtering.
What email marketers say
13 marketer opinions
Building on the understanding that email deliverability hinges on a multifaceted assessment, it's clear that while modern spam filters employ sophisticated algorithms, certain keywords continue to impact an email's overall spam score. Experts agree that terms suggesting scams, high urgency, or aggressive sales tactics, particularly when coupled with other negative indicators like suspicious links or poor sender reputation, heighten the risk of an email being marked as spam. It's essential to differentiate between spam filtering and unsubscribe actions; the latter are deliberate choices made by recipients, not automated responses from filters. Nevertheless, a consistent failure to land in the inbox due to these keyword-influenced spam detections can indirectly lead to higher unsubscribe rates, as subscribers may disengage or perceive a cessation of expected communications. The primary drivers for unsubscribes remain user satisfaction, content relevance, and the quality of the initial subscriber acquisition.
Key opinions
- Keywords Influence Spam Scoring: Despite filter sophistication, specific keywords contribute to an email's spam score, particularly when combined with other negative signals, affecting the likelihood of reaching the inbox.
- Advanced Filter Mechanisms: Spam filters analyze emails holistically, leveraging machine learning and a wide array of signals beyond mere keyword detection, including sender reputation and overall content quality.
- Unsubscribes are User Initiated: Unsubscribe events are explicit actions by email recipients, driven by personal preference, content relevance, or frequency, and are not a direct function of spam filters.
- Indirect Churn Impact: When emails consistently fail to bypass spam filters due to keyword usage or other issues, recipients may stop receiving expected messages, leading to a rise in manual unsubscribes as users lose interest or assume communications have stopped.
Key considerations
- Mindful Word Choice: Use caution with terms often flagged as 'spammy,' especially in critical areas like subject lines. While not absolute triggers, their presence can negatively impact an email's spam score, particularly when overused or combined with other red flags.
- Comprehensive Deliverability Focus: Prioritize foundational deliverability practices such as maintaining sender reputation, ensuring proper authentication, and fostering high engagement. Keywords are a secondary consideration within this broader framework.
- Analyze Unsubscribe Trends: Regularly review unsubscribe patterns and their underlying causes, recognizing that these are primarily driven by recipient satisfaction and content alignment rather than direct spam filter actions. Deliverability issues, however, can exacerbate these trends.
- Streamline Preference Management: Offer subscribers clear and easy ways to manage their email preferences or unsubscribe. A user-friendly process can help prevent spam complaints, maintain list hygiene, and provide valuable insights into subscriber behavior.
Marketer view
Email marketer from Email Geeks explains that words like 'scam,' 'abuse,' and 'waste' generally do not trigger spam filters on their own, unless combined with very spammy email structure. He clarifies that unsubscribes are typically recipient actions, not spam filter actions, and are driven by user expectations, happiness, acquisition process, and copywriting.
8 Dec 2021 - Email Geeks
Marketer view
Email marketer from Email Geeks responds that unsubscribes are actions taken by recipients, not spam filters.
19 Apr 2022 - Email Geeks
What the experts say
3 expert opinions
While specific email keywords can contribute to an email's spam score, their impact is secondary to an overarching assessment by sophisticated spam filters. Experts highlight that sender reputation significantly outweighs the influence of isolated keywords. Modern filtering systems, employing advanced heuristics and content analysis, evaluate the entire message, including its HTML structure, image-to-text ratio, and the sender's historical behavior. The presence of words commonly associated with scams or suspicious activity, particularly when coupled with other red flags like unusual formatting or questionable links, increases an email's likelihood of being flagged. However, no single keyword or small set of terms acts as a definitive trigger; it is the overall context and combination of factors that determine deliverability. Regarding unsubscribe rates, these are primarily user-driven decisions and are not directly influenced by spam filter actions. Nevertheless, if emails consistently fail to reach the inbox due to comprehensive filtering, recipients may perceive a lack of communication, which could indirectly lead to increased unsubscribe rates as users disengage.
Key opinions
- Keywords Part of Larger Score: Specific keywords and phrases contribute to an email's overall spam score, especially when combined with other indicators of suspicious or low-quality content, though they are not the sole determinant.
- Sender Reputation is Paramount: An email's sender reputation is a more critical factor in avoiding spam filters than the presence or absence of particular keywords.
- Sophisticated Filter Analysis: Modern spam filters employ advanced heuristics and comprehensive content analysis, evaluating the entire email context, including formatting, links, and sender behavior, rather than relying on simple keyword blacklists.
- Unsubscribes are User-Controlled: Unsubscribe rates are driven by recipient choices based on content relevance, frequency, or perceived value, with spam filters playing an indirect role only if emails consistently fail to deliver.
Key considerations
- Prioritize Sender Health: Focus on building and maintaining a robust sender reputation through consistent engagement, proper authentication, and adherence to email best practices, as this has a greater impact than individual keywords.
- Holistic Content Review: Instead of fixating on isolated 'spam words,' review the entire email for overall context, tone, and suspicious elements like excessive links or unusual formatting that can collectively raise a spam score.
- Understand Keyword Nuance: Recognize that while certain keywords contribute to a spam score, modern filters assess their context. Avoid terms commonly associated with scams or aggressive tactics, but don't obsess over individual words at the expense of overall message quality.
- Address User Engagement: To manage unsubscribe rates, concentrate on delivering highly relevant content, setting clear expectations, and providing an easy unsubscribe process. While deliverability affects visibility, direct unsubscribe drivers are tied to user satisfaction.
Expert view
Expert from Email Geeks explains that email reputation is more important than specific keywords when it comes to triggering spam filters.
29 Jun 2021 - Email Geeks
Expert view
A user on Information Security Stack Exchange, schroeder, explained that spam filters employ various heuristics, including content analysis, to identify scam emails. While not solely reliant on keywords, the presence of specific words and phrases commonly found in scam attempts, combined with other suspicious characteristics like unusual formatting or links, contributes significantly to an email's spam score.
29 Apr 2023 - Information Security Stack Exchange
What the documentation says
4 technical articles
Continuing to explore the nuances of email deliverability, it's evident that while sophisticated machine learning underpins modern spam filtering, specific email keywords still hold significance. Leading email service providers like Mailchimp and Constant Contact, along with systems like Apache SpamAssassin, acknowledge that certain words and phrases, particularly when combined with unusual formatting or suspicious links, contribute to an email's overall spam score. Google's Gmail, while relying heavily on machine learning and user actions, also filters content perceived as 'unwanted mail,' implying that 'spammy-looking' content, including specific keywords, can contribute to this perception. Therefore, despite advanced filtering mechanisms, content-based keyword analysis remains a fundamental part of many spam filtering processes. Regarding unsubscribe rates, these are not directly caused by spam filters but can be indirectly influenced. If emails consistently land in spam folders due to issues like keyword usage, recipients may never see the messages, leading to a lack of engagement and, subsequently, higher unsubscribe rates as users disengage or assume communications have stopped.
Key findings
- Explicit Keyword Role: Documentation from major Email Service Providers, such as Mailchimp and Constant Contact, along with open-source filters like Apache SpamAssassin, explicitly confirms that specific keywords, phrases, and content patterns are analyzed by spam filters.
- Content-Based Filtering: Beyond sender reputation, the actual content of an email, including specific word choices, plays a direct role in determining its spam score, contributing to whether it is perceived as 'unwanted mail.'
- Contextual Analysis: While keywords matter, their impact is often amplified or mitigated by surrounding factors like unusual formatting, suspicious links, excessive capitalization, and the overall perception of the message.
- Indirect Unsubscribe Link: Email content, including keyword usage that triggers spam filters, can indirectly lead to higher unsubscribe rates by preventing messages from reaching the inbox, causing recipient disengagement and perceived lack of communication.
Key considerations
- Strategic Word Choice: Be strategic about keyword usage, avoiding terms commonly associated with scams or aggressive marketing, as these are flagged by filters, particularly when combined with other suspicious elements.
- Holistic Content Optimization: Focus on optimizing the entire email, not just keywords. Ensure good formatting, relevant links, and clear, valuable messaging, as filters analyze content holistically.
- Leverage Documentation Insights: Consult documentation from major email service providers and open-source filters to understand their content guidelines and sensitivities regarding specific keywords and phrases.
- Address Deliverability-Unsubscribe Connection: Recognize that consistent inbox placement, influenced by content choices including keywords, is crucial for sustained subscriber engagement and to avoid indirectly higher unsubscribe rates.
Technical article
Documentation from Mailchimp explains that spam filters check for common spam trigger words, along with unusual formatting and suspicious links, as part of their assessment for email deliverability. While they do not provide a specific list, they acknowledge their role.
23 Sep 2023 - Mailchimp
Technical article
Documentation from Google Workspace Admin Help emphasizes that Gmail's spam filtering is sophisticated and relies heavily on machine learning, which learns from user actions like marking emails as spam. While specific keywords are not listed, content that is perceived as 'unwanted mail' or leads to user complaints will trigger filters, implying that 'spammy-looking' content, which includes certain keywords, can contribute to this perception.
31 Dec 2021 - Google Workspace Admin Help
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