Can I email a competitor's customer list if they went out of business and gave it to me?
Michael Ko
Co-founder & CEO, Suped
Published 7 Jul 2025
Updated 17 Aug 2025
9 min read
The scenario is quite common: a competitor goes out of business, and they offer to hand over their customer list. It sounds like a golden opportunity, a direct line to a new audience that already understands the product or service in your niche. While the gesture might seem beneficial and even polite, navigating the waters of email compliance, deliverability, and reputation in such a situation is far more complex than it appears.
My immediate thought is that this is not a straightforward transfer. The customers gave their explicit consent to your competitor, not to your company. This distinction is critical and often overlooked, and it can have significant repercussions for your email program if handled incorrectly.
Legal and ethical implications of using competitor lists
From a legal standpoint, the core issue is consent. When someone opts into an email list, they are consenting to receive emails from that specific entity, under its stated privacy policy. This consent does not automatically transfer to another business, even if the original business gives its blessing or goes defunct. Different jurisdictions have varying laws, but many, like GDPR in the European Union or CAN-SPAM in the United States, focus heavily on obtaining proper consent. While CAN-SPAM has broader definitions for commercial email, the spirit of email marketing best practices strongly leans towards explicit permission.
Even if your competitor formally provided you with the data, it typically isn't a legal acquisition of the customer relationships themselves, unless specific clauses were in place during their original data collection. This means the individual customers haven't given you, as a new entity, permission to contact them. It’s a common misconception that if a business legally transfers a database, the associated consent also transfers. In most cases, it does not. Always consult legal counsel, especially if operating in regions with strict data protection laws, before proceeding with such lists.
A key distinction often arises between a direct asset acquisition (where a business is bought lock, stock, and barrel, including its customer base and associated permissions) and simply being given a list. In the latter, absent explicit, transferrable consent, you are essentially dealing with an unsolicited (cold) list. This significantly impacts not just legality but also your sender reputation.
For more information, the Federal Trade Commission provides guidance on marketing practices and consumer protection in the United States, including aspects related to email marketing.
Deliverability risks and sender reputation
Even if the legal hurdles seem manageable in your jurisdiction, the deliverability risks are substantial. Sending to a list of contacts who did not explicitly opt into your communications is a recipe for disaster for your sender reputation. These recipients have no prior relationship with your domain or brand. They are highly likely to mark your emails as spam, leading to increased complaint rates. High complaint rates are a major red flag for Internet Service Providers (ISPs), indicating that your mail is unsolicited or unwelcome.
A surge in complaints, combined with low engagement (opens, clicks), can quickly damage your domain and IP reputation. This can lead to your emails being directed to the spam folder, or worse, your domain or IP address ending up on an email blocklist (or blacklist). Once on a blocklist, it becomes incredibly difficult to reach anyone's inbox, regardless of how legitimate your other mailing efforts are. It's a bag of poison that can compromise your entire email marketing infrastructure. You can learn more about how to fix email deliverability issues and how long it takes to recover domain reputation.
Furthermore, old or inactive lists are often riddled with spam traps. These are dormant email addresses that ISPs use to catch spammers. Sending to a spam trap instantly flags you as a bad sender, severely damaging your reputation. Given that the competitor went out of business, it's safe to assume their email list might not have been meticulously maintained, increasing the likelihood of encountering these traps. You can understand more about what spam traps are and how they work. This is one of the reasons why purchasing email lists is generally not a good strategy, and why the risks of sending emails to scraped addresses are high.
Quarterly emails, as mentioned, are also problematic for cold lists. This infrequent sending pattern makes it even harder to build a positive sending history. ISPs look for consistent, engaged sending. Sporadic emails to an unengaged list will likely exacerbate deliverability problems.
Approaches and best practices for list transfer
The problematic approach
Direct emailing: Sending directly to the inherited list from your domain. This risks high spam complaints and blocklisting.
Assuming consent: Believing that the competitor's blessing automatically transfers customer consent. It does not.
Ignoring jurisdiction: Not considering the legal frameworks in place, such as GDPR or CAN-SPAM, which regulate email marketing.
Damaged reputation: The risk of your domain ending up on a blocklist or facing severe inboxing issues.
Even with legal review, the safest and most compliant approach is to not email the list directly without obtaining fresh consent. However, if there's a strong business directive to try and reach these customers, here are some considerations for a very limited and cautious approach:
Initial communication: If at all possible, the original company should send a final email to their list, explaining they are closing and introducing your company as a new point of contact. This email should include a clear call to action for customers to opt-in to your list if they wish to continue receiving communications. This is the most legitimate way to transfer consent.
Single introduction email: If the above isn't feasible, you might consider sending a single, highly transparent email. This email must explicitly state how you obtained their address (from the defunct competitor), explain the situation clearly, and, most importantly, provide a prominent, undeniable opt-in link to your own list. Any subsequent emails should only go to those who actively opt in. This is a high-risk strategy, even for a single email, and should be treated with extreme caution.
Focus on value, not sales: The initial email should be purely informational and supportive, not promotional. Offer assistance or transition guidance related to the previous business, rather than pushing your products or services.
Clear sender identity: If allowed by the former competitor, include both your logo and their logo in the email to provide context and familiarity.
The goal is to gently transition these users and allow them to choose to engage with your brand. Anything resembling a batch and blast approach will likely fail and damage your email program, potentially leading to getting your IP or domain on a blocklist. For more detailed insights, you can review some perspectives on the legality of emailing competitor's customers.
Alternative strategies for customer acquisition
Instead of directly emailing the acquired list, consider alternative strategies to attract these customers to your brand organically. While it requires more effort, these methods build a healthier, more engaged customer base and protect your sender reputation.
Indirect communication channels: Work with the defunct competitor to place prominent notices on their old website (if it’s still live), social media, or other communication channels, directing customers to your site or a specific landing page where they can opt-in. This gives customers control over receiving your emails and ensures proper consent. You could also run targeted ads on platforms where their customers might be present, guiding them to your sign-up forms.
Valuable content: Create content (blog posts, guides, FAQs) that specifically addresses the needs of the competitor's former customers. For example, if they used a particular product, provide migration guides or transition tips to your offering. Promote this content through channels other than direct email, encouraging them to subscribe for more valuable information.
Partnerships: If the competitor had any existing partnerships, explore if those partners can help introduce your brand to the former customer base in a compliant way. This could be through co-marketing efforts or referrals.
Remember, the goal is to attract, not to impose. Focusing on attracting new subscribers who genuinely want to hear from you will result in much better deliverability, higher engagement, and ultimately, more successful email marketing campaigns. Leveraging an existing customer list (even if given with blessing) without proper opt-in is a risky maneuver, regardless of the perceived short-term gains.
For insights into handling existing lists under different circumstances, such as reusing an email list after a company acquisition, there are specific guidelines.
Views from the trenches
Best practices
Always prioritize explicit consent, as general consent does not transfer.
If inheriting a list, explore whether the defunct company can send a final opt-in email.
Use indirect methods, such as website banners or social media, to guide old customers to your opt-in.
Consult legal counsel for advice on data privacy laws in your specific jurisdiction.
Common pitfalls
Assuming implied consent is sufficient when inheriting a customer list.
Sending bulk emails to lists without a clear opt-in from recipients, risking deliverability issues.
Ignoring local and international data privacy regulations (e.g., GDPR, CAN-SPAM).
Underestimating the negative impact on sender reputation from high spam complaint rates.
Expert tips
Consider a single, very transparent email inviting opt-in, but be aware of the high risk.
Focus initial communications on support and value rather than direct sales.
If possible, acquire the old company's domain or email infrastructure for a smoother transition.
Remember that cold email prospecting is generally less effective for building long-term customer relationships.
Marketer view
Marketer from Email Geeks says that sending to a competitor's list without permission from the contacts is considered a third-party contact list and is not advisable. Consent does not transfer from one company to another.
2023-09-20 - Email Geeks
Expert view
Expert from Email Geeks says that the blessing of the competitor is irrelevant because the actual recipients did not give permission for their data to be owned or used by a new entity.
2023-09-20 - Email Geeks
Prioritizing permission for sustainable growth
While receiving a competitor's customer list might seem like an effortless way to expand your reach, the reality is far more complex. The lack of direct consent from these individuals poses significant legal and deliverability risks, potentially leading to damaged sender reputation, being put on a blocklist, and a high likelihood of your emails ending up in the spam folder.
Prioritizing permission and considering indirect, value-driven strategies for customer acquisition will always be the most effective path to sustainable email marketing success. If you're ever in doubt, obtaining clear, explicit consent from every recipient is the gold standard for maintaining a healthy email program and a strong brand reputation.
