Should I block emails containing the word unsubscribe?
Michael Ko
Co-founder & CEO, Suped
Published 27 Jul 2025
Updated 17 Aug 2025
8 min read
The prospect of blocking all emails containing the word "unsubscribe" might seem like an appealing shortcut to clear out unwanted messages. After all, if you didn't sign up for it, why should you have to see an unsubscribe link? This approach, however, comes with significant risks to your inbox, potentially impacting your ability to receive legitimate and important communications.
While it's true that some malicious senders or spammers might include an "unsubscribe" link as a ruse to verify your email address, legitimate marketers are legally required to provide one. Implementing such a broad filter could inadvertently lead to you missing out on important updates, receipts, or other essential emails from companies you actually want to hear from.
The risks of aggressive keyword filtering
Blocking emails based solely on the word "unsubscribe" is a blunt instrument in a world that requires precision. Legitimate email service providers (ESPs) and businesses comply with regulations like the CAN-SPAM Act in the U.S. and GDPR in Europe, which mandate a clear and conspicuous way to opt out of marketing communications. This often involves the use of an "unsubscribe" link or phrase in the email footer. Without this, senders risk significant penalties and damage to their sender reputation.
The issue arises when you receive unsolicited emails, commonly known as spam or junk mail. These emails often lack a functional unsubscribe mechanism, or worse, they use a fake one. Clicking a suspicious "unsubscribe" link in a spam email can confirm to the sender that your email address is active, potentially leading to even more spam. For more on this, you can check out this article from USA Today.
However, using a content filter that blocks any email containing the word "unsubscribe" can create a deliverability nightmare for you, the recipient. Many critical, non-promotional emails, such as those related to service changes, privacy policy updates, or even account security notifications, might include a note about how to manage your email preferences, which could incorporate the word "unsubscribe." This can lead to a significant number of false positives.
The risk of clicking suspicious unsubscribe links
Clicking an unsubscribe link in a spam email can inadvertently validate your email address to the sender. This signals that your email is active and monitored, making it a more valuable target for future spam campaigns. It can lead to an increase in unwanted emails rather than a decrease.
Some malicious unsubscribe links can also lead to phishing sites, or even trigger the download of malware. Always be cautious and avoid clicking links in emails from unknown or untrusted sources. Instead, mark the email as spam or junk.
Distinguishing legitimate from illegitimate
Instead of blocking an essential compliance phrase, focus on identifying the nature of the email. If the email is from a sender you recognize and previously interacted with, using the provided unsubscribe link is the most effective and safest way to stop receiving future communications. This signals to the sender that you no longer wish to receive their mail, and they should honor your request. For more information, read our guide on how unsubscribe links and rates affect email deliverability.
Conversely, if the email is unsolicited, suspicious, or clearly spam, the best course of action is to mark it as spam or junk within your email client. This action is crucial because it helps train your email provider's spam filters (and potentially global blacklists or blocklists) to identify similar emails in the future. Reporting spam contributes to a collective effort to combat unwanted mail. To learn more about blocklists, check out our guide on how email blacklists actually work.
Blocking the sender's email address or domain is another effective strategy for truly unwanted mail. Most email clients, including Gmail, Outlook, and Yahoo Mail, offer features to block specific senders. This ensures that all future emails from that sender go directly to your junk folder, or are blocked entirely, without the risk of filtering out legitimate mail based on content keywords.
Handling legitimate emails
When you receive emails from senders you know, like newsletters, promotions from brands you follow, or updates from services you use, and you no longer wish to receive them, it's best to use the built-in unsubscribe option.
Compliance: Legitimate senders are legally required to provide an easy way to opt out.
Sender reputation: Unsubscribing (as opposed to marking as spam) is better for the sender's reputation, as it indicates a preference change rather than a complaint. This can indirectly help your own email deliverability by fostering good sender practices across the ecosystem.
Handling unsolicited or spam emails
For emails you never subscribed to, or those that appear to be outright spam, avoid clicking any unsubscribe links. The safest and most effective actions are to mark them as spam or junk, or to block the sender.
Spam filters: Marking emails as spam helps train your email provider's filters to better identify and block similar unsolicited messages in the future.
Security: Clicking unknown unsubscribe links can lead to malicious websites or confirm your email's activity to spammers.
Direct blocking: Blocking a specific sender (or their domain) is more precise than keyword filtering and prevents future emails from that source without impacting others.
Recommended strategies for unwanted emails
Instead of using broad keyword filters that can backfire, employ your email client's built-in features for spam management. These tools are designed to handle unwanted mail far more effectively and intelligently. For example, most email services allow you to create custom filters based on sender address, subject lines, or other specific criteria that are less likely to catch legitimate emails. You can also explore options to mass unsubscribe from emails if needed.
Many email providers also offer advanced spam filtering that automatically detects and quarantines suspicious messages. These systems leverage sophisticated algorithms and machine learning to distinguish between legitimate messages and spam, often more accurately than a simple keyword filter. You can also review your email client settings to ensure these features are fully enabled and optimized.
For businesses sending emails, adherence to email authentication standards such as SPF, DKIM, and DMARC is paramount. These protocols help recipients verify that an email truly came from the claimed sender, reducing the likelihood of it being flagged as spam. While DMARC reports might not directly tell you about unsubscribe-word filtering, they provide invaluable insights into email authentication failures and potential delivery issues. To learn more, read our guide to DMARC, SPF, and DKIM.
Example of a targeted email filter ruletext
From: unwanted.sender@example.com
Subject: Free Vacation Offer!
This filter would move emails from 'unwanted.sender@example.com' to your 'Spam' folder.
Regularly review your junk or spam folder. Sometimes, legitimate emails can end up there by mistake, even if they don't contain unusual keywords. Marking these as "not spam" helps your email client learn what type of mail you want to receive, improving its accuracy over time. For general advice on how to stop junk mail, you can consult the Federal Trade Commission's consumer advice.
Impact on legitimate email reception
Employing an overly aggressive blocklist (or blacklist) based on common words like "unsubscribe" can significantly harm your ability to receive emails. While it might catch some unwanted messages, the collateral damage to legitimate communications is often too high. Imagine missing a critical account alert, a password reset email, or an important shipping notification, all because a filter flagged the word "unsubscribe".
Sender reputation is built on consistent, legitimate sending practices, and a key part of that is providing clear unsubscribe options. If you're a sender, ensuring your emails include a compliant unsubscribe mechanism and that you honor unsubscribe requests is vital for maintaining good deliverability and avoiding getting on a blocklist. For more insights on how not having an unsubscribe link affects deliverability, refer to our dedicated article.
Focusing on more sophisticated methods like improving domain reputation, utilizing robust spam filtering provided by your email service, and manually blocking individual problematic senders will yield much better results without sacrificing the integrity of your inbox. The goal is to filter out bad mail, not all mail that happens to contain a specific, legally required term.
Views from the trenches
Best practices
Always use the official unsubscribe link provided by a legitimate sender to opt out of unwanted but legitimate emails.
Mark clearly identifiable spam or phishing emails as junk or spam in your email client to help train filters.
Utilize your email client's sender-blocking features for persistent unwanted emails from specific addresses or domains.
Regularly review your spam folder to rescue any legitimate emails that may have been misclassified.
Common pitfalls
Clicking unsubscribe links in suspicious or unknown spam emails, which can validate your email address to spammers.
Creating overly broad content filters that block essential keywords like "unsubscribe," leading to missed legitimate emails.
Ignoring email authentication for your sending domain, increasing the likelihood of your emails being marked as spam.
Not regularly cleaning your email lists, which can lead to higher bounce rates and spam complaints.
Expert tips
Consider setting up dedicated email addresses for subscriptions versus personal communications to better manage incoming mail.
If you're a sender, test your unsubscribe process regularly to ensure it's functioning correctly and efficiently.
Leverage DMARC reports to monitor your email authentication and identify any potential issues that could affect deliverability.
Educate your team on email security best practices, especially regarding identifying and handling suspicious emails.
Marketer view
A marketer from Email Geeks says they were shocked to see an email rejected for containing the word 'unsubscribe' in the error message 550 5.7.1, indicating a security policy violation by the recipient domain. They found this level of filtering surprising for its potential impact on legitimate mail.
2024-11-01 - Email Geeks
Expert view
An expert from Email Geeks observed that such aggressive filtering is typically seen on smaller, personal email servers, suggesting it's an extreme measure one might take when solely responsible for their own inbox filtering.
2024-11-01 - Email Geeks
The best approach to managing your inbox
While the temptation to block emails containing the word "unsubscribe" might be strong for those battling inbox clutter, it's a strategy best avoided. It runs the significant risk of filtering out essential communications and goes against the very spirit of email marketing compliance. A more nuanced and effective approach involves leveraging your email client's built-in spam and blocking features, combined with careful discernment between legitimate and malicious emails. This ensures that you maintain control over your inbox without inadvertently cutting off valuable sources of information.
By understanding the difference between legitimate marketing emails and outright spam, and by using the appropriate tools to manage each, you can achieve a cleaner, more secure inbox without resorting to overly aggressive keyword filtering. Prioritize smart filtering and responsible interaction to safeguard your email experience.
Gmail, 
Outlook, and 
Yahoo Mail, offer features to block specific senders. This ensures that all future emails from that sender go directly to your junk folder, or are blocked entirely, without the risk of filtering out legitimate mail based on content keywords.
