Is it legal and advisable to send terms of service emails to unsubscribed users?
Matthew Whittaker
Co-founder & CTO, Suped
Published 14 Jun 2025
Updated 16 Aug 2025
7 min read
It's a common dilemma for businesses: how do you ensure all users are informed about critical updates like changes to your terms of service (TOS) or privacy policy, especially those who have previously unsubscribed from your marketing communications? This situation pits legal obligations against email deliverability best practices, creating a challenging tightrope walk for any sender.
I've seen many companies grapple with this, and the advice often varies. The core tension lies in distinguishing between commercial messages, which are subject to strict anti-spam laws, and transactional or service-related communications, which often have different legal exemptions. The path chosen can significantly impact your email program's health.
The legal distinction: commercial vs. transactional emails
When considering sending terms of service updates, the crucial first step is understanding the legal classification of the email. Most anti-spam laws, like the CAN-SPAM Act in the United States, differentiate between commercial (marketing) and transactional (relationship) messages. Commercial emails require clear consent and an unsubscribe mechanism, while transactional emails are generally exempt if their primary purpose is to facilitate a transaction or provide information related to an existing account or relationship.
A terms of service update typically falls into the category of a transactional or relationship message, provided it pertains to an existing commercial relationship, account, or service the recipient is actively using or has used. The FTC provides guidance on the CAN-SPAM Act, indicating that "required to send" messages, such as significant changes to company policy, can sometimes be sent to unsubscribed users. This is where the grey area begins, especially when dealing with users who have explicitly opted out of all communications.
However, just because it might be legally permissible under certain conditions doesn't mean it's without risk. Different global regulations, such as GDPR in Europe or CASL in Canada, have their own nuances regarding consent and what constitutes a service message versus a marketing one. It is essential to consult legal counsel to determine specific compliance requirements for your audience. For more information on handling these, you can explore best practices for sending legally mandated email notifications.
The significant impact on email deliverability
While your legal team might greenlight sending TOS updates to unsubscribed users, the email deliverability consequences can be severe. Internet Service Providers (ISPs) and mailbox providers, such as Google and Yahoo, prioritize user experience and actively monitor sender behavior. Sending unwanted emails, even if legally permissible, can lead to increased spam complaints.
The silent threat to your sender reputation
Sending terms of service updates to users who have previously unsubscribed, or to old, obsolete email addresses, introduces significant risks. Your domain and IP reputation could drop sharply, leading to higher spam complaint rates and potentially getting your IP or domain placed on an email blocklist (or blacklist). This directly impacts your ability to reach the inbox for all future communications. Learn more about why your emails might be going to spam.
High complaint rates damage your sender reputation, which can result in your emails being directed to the spam folder, or even worse, your IP addresses or domains being placed on a blocklist (or blacklist). This is particularly risky if your company is in the process of warming up new IPs, as a sudden influx of complaints can derail your efforts and lead to significant inbox placement issues across all email campaigns. Sending to old, obsolete, or inactive email addresses (including those that have previously hard bounced) only exacerbates this problem, generating more bounces and potentially triggering spam traps, which are a major red flag for ISPs. You can learn how to improve your domain reputation and avoid these pitfalls.
Legal compliance
Focus is on fulfilling legal obligations, such as informing users of critical policy changes as required by law, regardless of their unsubscribe status. The primary concern is avoiding legal penalties.
Transactional exemption: Many laws exempt essential service messages from marketing email rules.
Mandatory notices: Some updates are legally required to be communicated to all users.
Deliverability health
Focus is on maintaining a positive sender reputation to ensure emails reach the inbox. User engagement and avoiding spam complaints are paramount, even for legally permissible sends.
Complaint rates: Sending unwanted emails, regardless of legality, can spike complaints.
If you are dealing with a decision to send to all users, including those who have unsubscribed or complained, it's vital to weigh the legal permission against the practical impact on your email program's long-term health. The short-term legal compliance might lead to long-term deliverability struggles, affecting all your future email communications, including critical transactional messages.
Strategic alternatives for terms of service communication
Given the significant deliverability risks, it's often advisable to explore alternative methods for communicating terms of service updates to unsubscribed users. These methods can achieve the legal objective without incurring the wrath of ISPs. A common and highly effective approach is to leverage web and in-app notifications.
For active users, a simple banner on your website or within your application can inform them of the updated terms and require acceptance upon their next login. This ensures that users who continue to engage with your service are made aware without a forced email send. For those who have unsubscribed and are no longer actively engaging, the legal necessity to inform them via email might be less stringent, especially if there's no ongoing commercial relationship beyond their historical account. Consider best practices for sending terms of service emails to in-app users.
Example: web banner for TOS updatesHTML
<div class="tos-banner">
<p>Our <a href="/new-terms">Terms of Service</a> have been updated. Please review and accept to continue using our services.</p>
<button id="accept-tos">Accept Terms</button>
</div>
Another strategy is to segment your audience very carefully. You might send email updates only to active users or those with an ongoing, demonstrable relationship (e.g., paying subscribers, active account holders). For others, rely on passive notification methods. If an email send is truly unavoidable for a large, potentially unengaged segment, consider staggering the deployment over time to mitigate sudden volume spikes that ISPs might view as suspicious, or explore using a third-party service provider with a strong reputation for handling such sends.
Navigating internal legal and business perspectives
It can be challenging when internal legal counsel insists on a broad email send to all users, including unsubscribed ones. Often, legal teams are focused solely on compliance and may not fully grasp the intricate world of email deliverability and sender reputation. It becomes crucial for email professionals to educate and present the potential business consequences of such actions.
Aspect
Legal counsel perspective
Deliverability perspective
Primary goal
Avoid fines, lawsuits, and regulatory action by adhering strictly to laws.
Ensure emails reach the inbox, maintain sender reputation, and optimize user engagement.
Risk focus
Legal non-compliance, privacy breaches, and failure to inform users as mandated.
Spam complaints, blocklisting, low inbox placement, and damage to brand trust.
Recommended approach
Broad distribution to all relevant parties to cover legal bases fully.
Targeted communication, respecting unsubscribe requests, and using alternative channels.
Highlighting the tangible risks, such as increased spam complaints, lower inbox placement rates, and potential blocklistings (blacklisting), can help illustrate the hidden costs beyond immediate legal compliance. Provide data-driven insights into how these actions can impair ongoing customer communication, impact sales, and tarnish brand trust. Ultimately, while legality is a baseline, maintaining a healthy email ecosystem is paramount for sustained business operations.
When faced with a directive that seems detrimental to your email program, it's important to provide your recommendations clearly and in writing, detailing the potential negative impacts on deliverability. Presenting viable alternatives that achieve the same legal objective, such as web banners or in-app notifications, can often lead to a more balanced and effective solution that protects both legal interests and email health.
Views from the trenches
Best practices
Stagger large email deployments to avoid sudden volume spikes that can negatively impact your sender reputation with ISPs.
Implement multi-level opt-out options, differentiating between marketing and essential service communications to give users more control.
Always provide your email deliverability recommendations in writing, detailing potential risks and suggesting alternative communication strategies.
Consider engaging a third-party service provider with a strong reputation for handling large, sensitive email sends to benefit from their shared IP pools.
Common pitfalls
Sending terms of service updates to old, obsolete, or hard-bounced email addresses can significantly damage your domain and IP reputation.
Ignoring email deliverability warnings from your team or ESP because of legal counsel's directive can lead to increased spam complaints and blocklistings.
Failing to communicate the potential business impact of poor email deliverability to legal and leadership teams, beyond just legal compliance.
Attempting to re-engage previously unsubscribed users for non-critical updates, especially if there is no demonstrable ongoing relationship.
Expert tips
Carefully distinguish between commercial and transactional messages. Transactional emails relate to an ongoing commercial relationship or account status.
Understand that even if an email is legally permissible, it doesn't guarantee inbox placement and can still damage your sender reputation.
Leverage alternative communication channels such as web banners, in-app notifications, or user portals for essential updates to active users.
If a broad email send is unavoidable, ensure it's a one-time event and not a recurring practice to minimize long-term impact on your email program.
Marketer view
Marketer from Email Geeks says that sending terms of service updates to unsubscribed users can lead to having to warm up new domains and IPs again due to reputation damage.
2022-12-15 - Email Geeks
Marketer view
Marketer from Email Geeks says that legal permission doesn't always prevent deliverability problems, and the ongoing damage to an email program can be a significant issue.
2022-12-15 - Email Geeks
Key takeaways
Sending terms of service updates to unsubscribed users exists in a complex space where legal mandates and email deliverability best practices often conflict. While certain laws might permit these transactional communications, disregarding user preferences can severely damage your sender reputation, leading to low inbox placement rates and high spam complaints.
The optimal approach involves prioritizing alternative communication channels like web or in-app banners for those who have opted out of email marketing. When email is deemed necessary, careful audience segmentation, volume staggering, and clear communication with internal stakeholders are essential. Ultimately, protecting your email program's health is critical for long-term business success and effective communication with your entire user base.
Google and 
Yahoo, prioritize user experience and actively monitor sender behavior. Sending unwanted emails, even if legally permissible, can lead to increased spam complaints.
