What email domains and addresses should marketers avoid for better list compliance?

Key findings

• Disposable domains: Temporary email domains are frequently used for one-time sign-ups and are a strong indicator of low engagement, often leading to spam trap hits if not managed.
• Role accounts: Addresses like info@, sales@, or abuse@ are generic and typically don't belong to individuals, increasing the risk of spam complaints or non-delivery. Excluding them can significantly improve compliance.
• Regulatory and blacklist domains: Domains belonging to regulatory bodies (e.g., ftc.gov) or blocklist providers (e.g., spamhaus.org) should always be suppressed to avoid legal or deliverability issues.
• Invalid and inactive addresses: Sending to non-existent or long-dormant email addresses results in hard bounces and low engagement, signaling poor list hygiene to internet service providers (ISPs). This can harm your domain reputation. Regular list cleaning is essential.

Key considerations

• Comprehensive suppression lists: Implement a system to automatically suppress or remove common problematic domains, including those from social media platforms (e.g., facebook.com), role accounts, and known spam trap addresses.
• Email validation services: Utilize email validation tools to verify addresses at the point of collection and regularly clean your existing lists. This helps identify invalid, disposable, and spam trap email addresses before you send to them.
• Compliance with regulations: Adhere to email marketing laws such as CAN-SPAM, GDPR, and CCPA, which mandate requirements for consent, transparency, and privacy. The CAN-SPAM Act sets rules for commercial messages in the U.S.
• Monitoring deliverability: Regularly monitor your email deliverability metrics, including bounce rates, complaint rates, and inbox placement, to quickly identify if problematic domains or addresses are affecting your performance.

Key opinions

• Manual suppression lists: Many marketers actively maintain internal lists of domains to avoid, such as facebook.com, to prevent emails from reaching irrelevant or risky recipients.
• Role account suppression: There's a strong consensus that role-based email addresses (e.g., info@, support@) should be avoided due to their potential to cause problems unless explicitly expected.
• Disposable email blocking: Some email service providers (ESPs) automatically block temporary email domains, which are commonly used for short-term sign-ups and often result in low engagement or spam complaints. For more information, see strategies for blocking disposable email domains.
• Reputational protection: Marketers emphasize avoiding domains associated with anti-spam organizations (like spamhaus.org) or government bodies (like ftc.gov) to prevent awkward situations or unintended scrutiny.

Key considerations

• Leveraging ESP features: Marketers should utilize their email service provider's features, such as domain exclusion settings, to efficiently manage problematic addresses.
• Competitor suppression: While not directly deliverability-related, some marketers use domain suppression to prevent competitors from receiving and potentially repurposing their email content.
• Understanding automatic skips: Awareness that some ESPs automatically skip sending to known problematic email addresses (like certain role accounts or temporary domains) can help marketers interpret their live reports.
• Ongoing list maintenance: The consensus is that list maintenance is not a one-time task but an ongoing process, as new problematic addresses can always emerge. Mailchimp's guide emphasizes that an email list requires regular maintenance to remain effective.

Key opinions

• Spam trap exposure: Experts warn against sending to old, purchased, or scraped lists, as these are highly likely to contain spam traps. Hitting spam traps severely damages sender reputation.
• Bounce rate management: High bounce rates, especially hard bounces from invalid domains or non-existent addresses, signal to ISPs that your list quality is poor, which can lead to throttling or blocklisting.
• Engagement metrics: Sending to unengaged or problematic email domains contributes to low open and click rates, negatively impacting your sender score and inbox placement.
• Authentication standards: Proper email authentication (SPF, DKIM, DMARC) is essential, but even with perfect authentication, sending to bad addresses can still harm reputation.

Key considerations

• Proactive suppression: Experts recommend creating and maintaining a dynamic list of domains and addresses to actively suppress, including temporary, invalid, and high-risk domains.
• Robust validation: Implementing an email validation service at the point of entry (e.g., signup forms) is critical to prevent bad addresses from entering your list in the first place.
• List segmentation and re-engagement: Regularly segmenting your list by engagement and running re-engagement campaigns can help identify and remove dormant or problematic contacts before they become deliverability liabilities.
• Monitoring blocklists: Even with best practices, it's vital to regularly check if your sending IPs or domains have landed on any blocklists (or blacklists). Being listed on a blacklist can severely impact deliverability.

Key findings

• Consent requirements: Regulations like GDPR and CAN-SPAM heavily emphasize obtaining clear and verifiable consent from recipients before sending marketing emails. This directly impacts the quality of domains and addresses on your list.
• Opt-out mechanisms: Documentation mandates that commercial emails must include a clear and conspicuous way for recipients to opt out of future messages, and opt-out requests must be honored promptly.
• Sender identification: Commercial emails must accurately identify the sender and include a valid physical postal address. Misleading headers or addresses are non-compliant.
• Prohibited content: Laws often prohibit deceptive subject lines or misleading content, indicating that the source of the email addresses (and thus their associated domains) should be trustworthy.

Key considerations

• Data minimization: The CCPA, for example, encourages businesses to collect only data required for email campaigns, such as email addresses and names, and to avoid sensitive data. This suggests focusing on acquiring only relevant email contacts.
• Regular audits: Regularly audit your email list acquisition methods and recipient data to ensure ongoing compliance with privacy and anti-spam laws.
• ISP requirements: Beyond legal compliance, adhering to ISP-specific bulk sender guidelines (like those from Google and Yahoo) is crucial. These often emphasize low complaint rates and proper authentication, which are influenced by the quality of your recipient list. For detailed information, review new rules for bulk email senders from Google and Yahoo.
• Sender reputation isolation: For high-volume senders, documentation often suggests using a dedicated subdomain for email marketing. This isolates your sender reputation from other email activities, minimizing the impact if problematic addresses cause issues.