How do affiliate emails impact sender deliverability and what legal risks exist?
Michael Ko
Co-founder & CEO, Suped
Published 8 Jun 2025
Updated 17 Aug 2025
6 min read
Affiliate marketing can be a powerful channel for growth, extending your brand's reach and driving sales. However, when it comes to email, the relationship with affiliates introduces a complex layer of risk that can directly impact your email deliverability and expose you to significant legal liabilities.
Many brands operate under the assumption that if affiliates are using their own sending infrastructure, like different IP addresses and subdomains, their email practices won't affect the core brand's reputation. Unfortunately, this isn't always the case. The interconnected nature of email ecosystems means that poor sending habits by an affiliate can indeed cast a shadow on your brand.
Understanding these potential pitfalls is crucial for any brand leveraging affiliate email marketing. This guide will explore how affiliate emails can affect your sender reputation and what legal responsibilities you bear when working with third-party promoters.
How affiliate email practices affect your deliverability
The impact of affiliate email practices on your deliverability, even when affiliates use distinct IPs and subdomains, stems from several factors. One significant factor is the association forged by simply mentioning your brand or, more critically, by linking directly to your website. Email service providers (ESPs) and internet service providers (ISPs) analyze content and links within emails to assess sender reputation.
If an affiliate engages in spammy tactics, leading to high complaint rates or engagement with spam traps, the reputation of the links within those emails can suffer. Since these links often direct to your brand's website, your domain's reputation can indirectly be affected. Some sophisticated filtering systems actively trace redirects to identify the ultimate destination, connecting the poor sending practices back to your brand's domain, even if there are multiple hops in the linking chain.
Furthermore, if an affiliate's email campaigns result in their sending IPs or domains getting placed on a blacklist (or blocklist), it can degrade the perceived reputation of any brand associated with them. This is especially true for blacklists that track spamvertised content, where the reputation of the advertised domain is tarnished by the sender's practices. An article by Kickbox explores this impact in depth, highlighting how affiliate marketing can harm your brand's email program.
Navigating the legal landscape of affiliate marketing
While deliverability is a significant concern, the legal risks associated with affiliate email marketing are often even greater. When you pay an affiliate to promote your brand, you are the "advertiser," which can make you liable for their email sending practices, even if they operate independently using their own systems. This concept is often referred to as "follow the money," where regulatory bodies trace violations back to the ultimate beneficiary of the promotional activity.
Laws like CAN-SPAM in the U.S. and CASL in Canada hold brands accountable if their affiliates fail to comply with regulations, especially regarding consent and unsolicited emails. If you are aware of, or should reasonably be aware of, an affiliate's non-compliant practices and do not take action to correct or terminate the relationship, you can be held legally responsible for their violations.
Brand's liability for affiliate actions
It is critical to establish clear contractual agreements with affiliates that mandate compliance with all relevant email marketing laws and industry best practices. Without such agreements and consistent monitoring, your brand could face substantial fines, legal action, and reputational damage due to an affiliate's missteps. This liability extends to various forms of email marketing spam originating from affiliates.
Technical pathways of reputation damage
Email providers employ sophisticated mechanisms to track links and assess their reputation. While affiliates often use their own tracking domains and multiple redirects to attribute sales and potentially obfuscate their sending origins, modern anti-spam systems can often follow these chains to their ultimate destination, which is typically your brand's website. This means that if an affiliate's intermediate links are flagged for malicious activity or high spam complaints, it can negatively impact your brand's domain reputation.
The expense involved in this deep link analysis means it's not always applied universally, but it is certainly done when certain triggers are met, such as excessive spam complaints or patterns of suspicious sending. This makes the due diligence of vetting affiliates, and understanding their email practices, incredibly important. An article by Brevo highlights how common mistakes can damage sender score, a concept equally applicable to your affiliates.
Legitimate affiliate linking
Transparency: Affiliates use clear tracking URLs that are not hidden or excessively redirected, typically leading directly to the brand's landing page.
Reputable domains: Affiliates maintain a good domain reputation for their own sending and tracking domains.
Authentication: Affiliate emails are properly authenticated with SPF, DKIM, and DMARC for their sending domains.
Problematic affiliate linking
Obfuscation: Use of numerous, highly obfuscated redirects or cloaking to hide the final destination or origin.
Bad domains: Sending or tracking domains with poor reputations, leading to blocklisting or spam filtering.
Impersonation: Sending emails that mimic the brand's identity without proper authorization, potentially leading to phishing flags or sender address issues.
Proactive measures and prevention
To mitigate the deliverability and legal risks associated with affiliate email marketing, a proactive approach is essential. Begin by thoroughly vetting potential affiliates before establishing partnerships. This includes checking their email sending history, their data collection practices, and their overall reputation. Require clear consent for email subscribers and ensure they adhere to all applicable privacy regulations like GDPR where relevant.
Draft robust contractual agreements that explicitly outline acceptable email sending practices, compliance requirements, and consequences for violations. These contracts should cover aspects such as list acquisition methods, email content guidelines, and frequency caps. Regular audits of your affiliates' email campaigns can help catch issues before they escalate.
Additionally, continue to monitor your own domain reputation and maintain strong email authentication for your direct sending. While authentication won't directly cover an affiliate's separate sending, a consistently strong reputation for your core brand can provide some buffer. Be prepared to swiftly address any issues that arise, whether it's an affiliate being blacklisted or a surge in spam complaints related to your brand.
Views from the trenches
Best practices
Always include clauses in your affiliate contracts that explicitly prohibit spamming, require adherence to all email regulations, and allow for immediate termination upon violation.
Regularly monitor your brand's online mentions and common blocklists for any indication that your affiliates' email practices are negatively impacting your reputation.
Prioritize affiliates who demonstrate transparent and compliant email list acquisition methods and content practices.
Implement a system for collecting and reviewing affiliate campaign reports, focusing on metrics like complaint rates and bounce rates.
Common pitfalls
Assuming that because affiliates use their own IPs and domains, their email issues will not affect your brand's deliverability or legal standing.
Failing to conduct thorough due diligence on new affiliates, especially regarding their historical email sending practices and compliance records.
Not having clear legal agreements in place that explicitly hold affiliates accountable for their email marketing compliance.
Ignoring early warning signs of problematic affiliate behavior, such as increased spam complaints or mentions on forums.
Expert tips
Use dedicated landing pages for affiliate traffic to isolate and monitor conversion quality and identify problematic traffic sources.
Consider link reputation monitoring tools to track how various domains linking to your site are perceived by ISPs.
Educate your affiliates on email best practices and legal compliance, treating them as extensions of your marketing team.
Be prepared to cut ties with non-compliant affiliates quickly to protect your brand's long-term email deliverability and legal standing.
Expert view
Expert from Email Geeks says that sending enough spam by affiliates can indirectly impact deliverability and lead to legal issues related to unsolicited emails, as brands are often responsible for their affiliates' compliance.
2024-02-01 - Email Geeks
Expert view
Expert from Email Geeks says that the legal risk in affiliate marketing is often higher than the deliverability risk because the brand paying for advertising can be held responsible for affiliate behavior, even if affiliates use rotating IPs and domains to evade blocks.
2024-02-01 - Email Geeks
Maintaining a healthy email ecosystem
Affiliate email marketing, while beneficial for reach and sales, is not without its significant challenges and risks. The actions of your affiliates, even when using their own sending infrastructure, can have a direct and negative impact on your brand's email deliverability and expose you to considerable legal liabilities. This influence can manifest through damaged link reputation, increased spam complaints, and potential blacklisting, ultimately hindering your ability to reach the inbox consistently.
Therefore, establishing strong contracts, diligently vetting your partners, and continuously monitoring their practices are not just best practices, but essential safeguards. Compliance with legal regulations is paramount, as brands are often held responsible for the actions of those promoting their products or services.
By understanding these dynamics and implementing robust preventative measures, you can leverage the power of affiliate marketing while protecting your email program's integrity and ensuring your messages continue to land in the inbox, not the spam folder.
