Why am I hitting spamtraps with double opt-in email addresses, and do spamtraps click?

Key findings

• Spam trap purpose: Spam traps (also known as blocklists) are email addresses set up by anti-spam organizations and internet service providers (ISPs) to identify and catch senders of unsolicited bulk email. They are not intended to interact with emails.
• No human interaction: True spam traps are automated and do not intentionally open emails or click on links. Their detection is based purely on receiving mail.
• Recycled addresses: Many spam traps are recycled email addresses that were once valid but became inactive and were later repurposed. If you send to such an address, it indicates poor list hygiene, even if the address was originally double opt-in. Learn more about how to identify email spam traps.
• Double opt-in limitations: While double opt-in (DOI) is a best practice for list quality, it doesn't guarantee immunity from hitting spam traps if your list maintenance is insufficient or if recycled addresses are involved. It primarily prevents fake sign-ups and typos.
• ISP link scanning: Some ISPs, like Microsoft, may scan links within incoming emails for security or content analysis, which could register as a 'click' in your analytics without actual user engagement. This is not the spam trap itself clicking, but rather an automated system.

Key considerations

• List hygiene: Regularly clean your email list to remove inactive or bouncing addresses. Even with DOI, old or recycled addresses can become spam traps. Understanding what causes invalid user bounces is essential.
• Source identification: If you're hitting spam traps with DOI-confirmed addresses, investigate the source of these addresses. Are they truly recent opt-ins, or are they from older segments of your list that haven't been engaged with for a long time?
• Monitoring and response: Monitor your sender reputation through tools like Microsoft SNDS to detect spam trap hits. While a few hits might not be catastrophic, a pattern indicates deeper issues. For more on this, check out Mailgun's guide to avoiding emails going to spam.
• Automated security scanning: Be aware that automated systems, not human spam traps, may engage with links for scanning. This is usually distinguishable from legitimate user clicks.
• Impact on deliverability: Hitting spam traps, even with double opt-in, signals to ISPs that your list management or sending practices are flawed, which can negatively impact your sender reputation and email deliverability.

Key opinions

• DOI is not foolproof: Many marketers acknowledge that while double opt-in significantly reduces spam trap risks, it doesn't eliminate them entirely, especially for recycled or dormant addresses that later become traps.
• List decay is real: There's a strong consensus that email lists naturally decay over time, and addresses that were once legitimate opt-ins can become spam traps if not regularly engaged with or cleaned. This relates to best practices for managing email lists.
• Spam trap hits are a signal: Marketers generally view spam trap hits as a clear indicator of underlying list quality issues, rather than just an unfortunate event.
• Misinterpretation of clicks: Some marketers may observe 'clicks' from suspected spam trap addresses in their analytics, but this is often attributed to automated scanning by email providers or security tools, not direct engagement by the trap itself.

Key considerations

• Regular re-engagement: Actively re-engage inactive subscribers. Those who don't respond should be suppressed to prevent them from becoming recycled spam traps.
• Segmentation: Segment your audience based on engagement levels to avoid sending to dormant addresses that might eventually turn into spam traps. This also helps reduce emails going to spam.
• Form protection: Even with DOI, ensure your signup forms are protected from bots that might submit spam trap addresses, as outlined in our guide on protecting email list signup forms from bots.
• Bounce management: Effectively manage hard bounces. These often indicate invalid addresses, some of which could be pristine spam traps.
• Contextual analysis: When encountering spam trap hits, always review your acquisition sources and list management practices to understand the root cause. A useful resource is Mailmunch's guide to understanding email spam traps.

Key opinions

• Recycled addresses are common: Experts frequently point to recycled addresses, which once belonged to real users but are now spam traps, as a primary reason for hits, even with DOI. Competent networks 'season' these by bouncing mail for an extended period before converting them into traps.
• Spam trap hits reflect deeper issues: Many experts believe that spam trap hits are rarely the sole problem but rather a symptom of broader issues in list acquisition or management practices, such as sending to unknown or unengaged email addresses.
• Microsoft's link scanning: It's noted that Microsoft (MS) may occasionally follow links in emails for internal security purposes, which could register as clicks in a sender's analytics, though this is distinct from spam traps actively engaging. This is similar to artificial email opens and clicks.
• Microsoft's recycling policy: While Microsoft used to recycle addresses as traps, they reportedly no longer do, meaning any older recycled trap hits likely come from other networks or very old addresses.
• Tolerance for minor hits: A few spam trap hits at Microsoft are generally not considered a major concern by experts and can be an expected part of email operations.

Key considerations

• Deep dive into list practices: If you're seeing spam trap hits, go beyond the simple explanation and deeply analyze your list acquisition and hygiene practices. This helps identify the true source of problematic addresses.
• Understand ISP behavior: Familiarize yourself with how specific ISPs, like Microsoft, handle recycled addresses and automated link scanning. This insight can explain anomalous 'click' data or unexpected spam trap reports from Microsoft Hotmail spam traps.
• Prioritize list quality: While double opt-in is crucial, it's part of a larger strategy that includes ongoing list validation and removal of unengaged subscribers to prevent old addresses from turning into traps. This is critical for overall email deliverability.
• Don't overreact to minimal hits: A very low volume of spam trap hits, especially from systems like Microsoft SNDS, might not warrant a significant alarm or immediate overhauling of practices. Email experts from Spamresource.com provide ongoing insights into these dynamics.

Key findings

• Spam trap definition: Documentation defines spam traps as hidden or abandoned email addresses repurposed to identify senders with poor email practices, such as buying lists or neglecting list hygiene.
• Double opt-in verification: Double opt-in processes are documented as methods to ensure subscribers confirm their email addresses, helping to verify that a sender's list contains only legitimate and desired recipients.
• Engagement behavior: Authoritative sources typically state that true spam traps do not engage with emails; they do not open or click. Any observed engagement is usually attributed to automated scanning.
• Reputation impact: Hitting a spam trap is documented as a strong negative signal that can severely damage a sender's reputation, leading to blocklisting or increased spam folder placement. This is similar to how Spamcop listings affect deliverability.

Key considerations

• List validation: Documentation recommends employing email validation tools as a foundational step to detect and remove invalid or typo-ridden addresses that could evolve into spam traps.
• Active vs. inactive addresses: It's important to distinguish between active, engaged subscribers and inactive ones who might eventually become recycled spam traps. This calls for robust list segmentation.
• Permission-based marketing: Adhering strictly to permission-based email marketing principles, reinforced by double opt-in, is highlighted as the primary defense against accumulating spam traps.
• Monitoring zero engagement: If email addresses consistently show zero opens or clicks across multiple campaigns, documentation suggests they might be spam traps and should be investigated. You can check what spam traps are and how they work. Further information can be found in EmailOversight's guide.