Does using words like Black Friday in the from address or subject line impact email deliverability or engagement?
Matthew Whittaker
Co-founder & CTO, Suped
Published 18 Apr 2025
Updated 16 Aug 2025
5 min read
As the holiday season approaches, especially around peak sales events like Black Friday and Cyber Monday, marketers often consider tweaking their email strategy to maximize visibility. One common question that arises is whether incorporating terms such as Black Friday directly into the from address or subject line could impact email deliverability or engagement.
While it might seem intuitive that certain words could trigger spam filters, the reality of modern email deliverability is far more complex. Today, spam filters, whether from Google or Yahoo, rarely rely on simple keyword matching. Instead, they employ sophisticated algorithms that evaluate an email's overall context, sender reputation, and recipient engagement patterns.
So, how exactly do terms like Black Friday fit into this intricate system? The answer lies less in the words themselves acting as a direct deliverability flag, and more in their influence on how subscribers interact with your emails.
The myth of static spam trigger words
The notion of spam trigger words is largely a relic of the past. In the early days of email, filters were simpler and could be fooled by obvious keywords. This led to many articles publishing lists of words to avoid, like free or win. However, modern spam filters, particularly those used by major Internet Service Providers (ISPs), have evolved significantly.
Today, filters analyze a vast array of signals beyond individual words. They look at the sender's reputation, email authentication (SPF, DKIM, DMARC), content, links, and, crucially, how recipients interact with the email. A high engagement rate signals to ISPs that your emails are valued, regardless of the words used. Conversely, low engagement, high complaint rates, or bounce rates can damage your sender reputation, leading to filtering issues.
While isolated words like Black Friday are not inherently bad, some specific, unusual word combinations, particularly those often associated with malicious spam, can still pose a risk, especially with email providers like Microsoft. However, this is distinct from a fixed list of spam trigger words. Most resources promoting such lists are often outdated, leading to unnecessary restrictions on legitimate email content.
Understanding the myth
Many email marketers still operate under the assumption that a static list of spam trigger words exists and must be avoided at all costs. This originates from older spam filtering technologies like SpamAssassin, which did use keyword-based scoring.
The modern reality
Today's sophisticated spam filters analyze numerous factors beyond keywords. These include your sender's IP and domain reputation, email authentication protocols like DMARC, the content's overall context, and most importantly, subscriber engagement. The actual deliverability impact of any word is tied to its role within the larger context of your email and how recipients interact with it.
From address and subject line choices: marketing vs. deliverability
When you add terms like Black Friday to your friendly from name (e.g., Your Brand | Black Friday Deals) or your subject line, the direct impact on deliverability is minimal. ISPs are not going to automatically blocklist (or blacklist) your email simply because it contains these common, commercial terms during a relevant period. Your sender name itself has a significant effect on whether your message is opened or deleted.
The real consideration is engagement. A personalized, relevant subject line and a recognizable from address are far more likely to increase open rates and clicks. If adding Black Friday to your subject line helps your email stand out in a crowded inbox and encourages opens, that positive engagement will ultimately support your deliverability, regardless of the words themselves.
Conversely, if your audience finds these additions generic or overly promotional, leading to low engagement, spam complaints, or unsubscribes, this negative feedback can indirectly harm your sender reputation. It is critical to balance marketing appeal with your audience's expectations and past interaction patterns.
Marketing considerations
Visibility: Using Black Friday can instantly signal relevance during peak shopping seasons.
Engagement: Can drive higher open rates if your subscribers expect such promotions.
Deliverability considerations
No Direct Impact: The words themselves do not directly trigger spam filters or cause emails to be blocklisted.
Indirect Impact: Deliverability is affected by recipient engagement. If the use of these words leads to increased spam complaints or low opens due to perceived spamminess, then deliverability can decline.
Optimizing for engagement during peak seasons
For Black Friday and other high-volume sending periods, focusing on maintaining strong engagement is paramount. ISPs monitor how your subscribers react to your emails. Positive interactions, such as opening, clicking, and moving emails from spam to inbox, build a strong sender reputation.
Conversely, negative actions like marking an email as spam, deleting without opening, or high unsubscribe rates can quickly degrade your reputation. This is why a sudden surge in email volume, especially to disengaged contacts, can be detrimental. It is crucial to warm up your email list and follow deliverability best practices even during peak periods.
If you decide to incorporate Black Friday or similar terms into your from address or subject line, always monitor your engagement metrics closely. Low open rates or high complaint rates are clear signals that your strategy might be backfiring, irrespective of specific keywords.
Views from the trenches
Best practices
Always maintain a clean and engaged email list to avoid hitting spam traps or being flagged by ISPs.
Personalize your subject lines and from addresses where possible to increase relevance and open rates.
Gradually increase your email volume during peak seasons, rather than sending sudden, large blasts.
Ensure strong email authentication (SPF, DKIM, DMARC) is in place for all your sending domains.
Common pitfalls
Suddenly changing your friendly from name for a single campaign can confuse recipients and increase spam complaints.
Sending to unengaged or old segments of your list during high-volume periods can significantly hurt your reputation.
Overusing ALL CAPS, excessive punctuation, or emojis in subject lines can make emails appear spammy.
Ignoring negative engagement metrics, such as high unsubscribe or spam complaint rates, can lead to long-term deliverability issues.
Expert tips
Focus on the overall user experience: a compelling subject line, relevant content, and clear calls to action.
A/B test different subject line variations and from addresses to see what resonates best with your audience.
Use preheaders effectively to complement your subject line and provide additional context.
Ensure your email design is mobile-responsive and renders correctly across various email clients.
Marketer view
Marketer from Email Geeks says there is no such thing as trigger words in email, so terms like "Black Friday" would not help or hurt deliverability.
2022-11-28 - Email Geeks
Expert view
Expert from Email Geeks says trigger words are largely a myth and a relic of old spam filtering methods.
2022-11-28 - Email Geeks
Key takeaways for holiday email strategies
Ultimately, using words like Black Friday in your from address or subject line is primarily a marketing decision. The direct impact on email deliverability is negligible, as modern spam filters prioritize sender reputation and engagement over specific keywords.
Your focus should remain on providing value to your subscribers, maintaining a healthy sender reputation, and closely monitoring your engagement metrics. If these terms help your emails resonate with your audience and drive positive interactions, they can be a valuable addition to your holiday campaign strategy.
Microsoft. However, this is distinct from a fixed list of spam trigger words. Most resources promoting such lists are often outdated, leading to unnecessary restrictions on legitimate email content.
