Summary
Maintaining good email list hygiene is critical for high deliverability and positive sender reputation. This involves identifying and removing invalid, inactive, and uninterested email addresses. Validate list hygiene by sampling data, checking for bounces and engagement, and using hygiene tools, evaluating tools by accuracy, pricing, speed, and GDPR compliance. Double opt-in, removing duplicates, correcting typos, and segmenting based on engagement improve list quality. Be aware hygiene products cannot catch all spam traps. Tools like Kickbox and ZeroBounce offer risk scores and detailed categorization. Proactive measures and attention to recently active emails can improve outcomes. Avoid list washing, and adhere to email syntax standards while recognizing deliverability is separate.
Key findings
- List Hygiene Impact: Poor email list hygiene leads to lower deliverability, negative sender reputation, financial costs and wasted effort.
- Validation Tools are key: Tools like Kickbox and ZeroBounce provide granular results about data, scores, validation and actioning.
- Actioning Results: Take action on results and remove or flag any dangerous emails from your list.
- GDPR: Ensure you're GDPR compliant with your emails.
- Double Opt In: Use double opt in to make sure emails are valid from the get go.
- Email hygiene isn't an end game: Email list hygiene should be a constant and pro active process
Key considerations
- Spam Traps: Although purchasing customers seem valid emails, ensure you are screening for potential spam traps amongst those
- Old data: If subscribers are old or haven't engaged you should screen those out
- List Washing: Ensure that you do not attempt list washing as this can further harm your email reputation
- Recently Active Addresses: Actively question if it is neccessary to clean recently active email addresses
What email marketers say
14 marketer opinions
Maintaining good email list hygiene is crucial for ensuring high deliverability and a positive sender reputation. This involves identifying and removing invalid, inactive, and uninterested email addresses from your list through various methods. Validating list hygiene can involve sampling data, checking for bounces and engagement, and then using hygiene tools to identify false positives. Factors to consider when choosing a list cleaning service include accuracy, pricing, speed, GDPR compliance, and integration capabilities. Employing practices like double opt-in, removing duplicates, correcting typos, getting rid of role-based emails, removing unengaged subscribers, and segmenting based on engagement levels are also key. Be aware that hygiene products cannot catch every spam trap, and some may be obfuscated. Regularly monitoring bounce rates, feedback loops, and implementing strict opt-in processes further aids in maintaining a clean and effective email list.
Key opinions
- List Hygiene Definition: Email list hygiene is identifying and removing invalid, inactive, and uninterested email addresses.
- Validation Methodology: Validate list hygiene by sampling data, checking bounce/engagement, and using hygiene tools.
- Factors for List Cleaning: Consider accuracy, pricing, speed, GDPR compliance, and integration for list cleaning services.
- Importance of Double Opt-In: Using double opt-in improves list quality and ensures valid, active subscribers.
- Email Verification Tools: Remove duplicates, correct typos, remove role-based emails, and unengaged subscribers using email verification tools.
- Spam Trap Detection: No hygiene product catches every spam trap; some are actively obfuscated.
- Engagement-Based Segmentation: Segment lists based on engagement levels to improve deliverability and relevance.
- Permission: Always get permission before sending emails to protect your sender reputation.
Key considerations
- Engagement Cadence: Assess how long ago subscribers bought or last engaged to avoid sending to abandoned inboxes.
- Spam Traps: Even purchasers can provide spam traps, requiring constant monitoring.
- Tool Tailoring: Tailor your choice of verification service based on your specific list size and accuracy needs.
- Data Sampling: Sample email addresses and test those addresses to see the quality of the data.
- Monitoring and Maintenance: Continuously monitor bounce rates, feedback loops, and implement strict opt-in processes to maintain list health.
Marketer view
Email marketer from Email Geeks explains that canonical deliverability depends on how long ago someone bought or last engaged on that email address, as the user might have abandoned that inbox, or it could have been converted into a trap.
3 Mar 2025 - Email Geeks
Marketer view
Email marketer from Sendinblue advises considering factors such as accuracy, pricing, speed, and integration capabilities when choosing an email verification service. Also, they advise reading reviews, checking for GDPR compliance, and ensuring it identifies a broad range of email issues, including disposable emails and spam traps.
11 Oct 2022 - Sendinblue
What the experts say
6 expert opinions
Experts emphasize the importance of maintaining email list hygiene to avoid negative consequences like financial losses, reduced inbox placement, and damaged sender reputation. Validating the effectiveness of list cleaning tools involves running the same audience through different tools and focusing on addresses that bounce despite being marked as okay. Using a service that provides a confidence score can allow for setting custom thresholds. Putting recently active addresses through verification may be unnecessary. Identifying spam traps involves looking for addresses that haven't opted in or have been dormant and promptly removing them. List washing services, where a third party sends emails to your list to identify bounces and unengaged addresses, is generally considered a harmful practice. Proactive measures to obtain valid addresses are preferred over reactive cleaning.
Key opinions
- Cost of Bad Data: Bad email data leads to financial losses, reduced inbox placement, and damaged sender reputation.
- Tool Validation: Validate cleaning tools by comparing results and focusing on addresses marked okay but still bouncing.
- Confidence Scores: Tools with confidence scores allow for customizing thresholds and risk levels.
- Spam Trap Identification: Identify spam traps by looking for non-opted-in or dormant addresses and promptly remove them.
- List Washing is Bad: Sending emails on behalf of the list owner to identify bad emails is not advisable.
Key considerations
- Recently Active Addresses: Consider whether email verification is necessary for addresses with recent activity.
- Proactive Measures: Focus on proactive measures to obtain valid addresses rather than relying solely on reactive cleaning methods.
- Focus on Bounces: When evaluating new tools make sure it improves on addresses that have had issues.
Expert view
Expert from Word to the Wise explains that bad email data costs money, reduces inbox placement, hurts sender reputation, and creates more work. It's imperative to clean lists to ensure that you are only sending to the addresses you want to send to.
2 Aug 2021 - Word to the Wise
Expert view
Expert from Email Geeks shares their experience investigating a new list cleaning tool by running the same audience through both their current tool and the new tool, focusing on the addresses the old tool said were OK but ultimately bounced. They liked that the new tool gave a confidence score with each record, allowing them to determine their own threshold.
6 Sep 2024 - Email Geeks
What the documentation says
4 technical articles
Email list hygiene validation is supported by various services offering detailed results on email address quality. Kickbox categorizes addresses as deliverable, undeliverable, risky, or unknown. ZeroBounce provides risk scores indicating the likelihood of an address being problematic. Email Hippo identifies disposable email addresses (DEAs). While RFC 5322 defines email address syntax, a valid syntax doesn't guarantee deliverability. Services provide insights for informed decisions on addresses to keep, remove, or investigate.
Key findings
- Kickbox Categories: Kickbox categorizes email addresses as deliverable, undeliverable, risky, and unknown.
- ZeroBounce Risk Scores: ZeroBounce offers risk scores to indicate the likelihood of an address being a spam trap or bot.
- Email Hippo DEA Detection: Email Hippo identifies disposable email addresses (DEAs) to improve list quality.
- RFC 5322 Syntax: RFC 5322 defines email address syntax but doesn't guarantee deliverability.
Key considerations
- Informed Decisions: Use the insights from validation services to make informed decisions on which addresses to keep, remove, or further investigate.
- Deliverability vs. Syntax: Recognize that a syntactically valid email address (per RFC 5322) may still be undeliverable.
- Risk Assessment: Consider risk scores to remove potentially problematic email addresses and protect sender reputation.
Technical article
Documentation from ZeroBounce shares that it offers risk scores for email addresses, indicating the likelihood of an address being a spam trap, bot, or problematic in other ways. A higher risk score suggests a greater need to remove the address from your list to protect your sender reputation.
7 Aug 2024 - ZeroBounce
Technical article
Documentation from Kickbox explains that their service provides detailed verification results, including deliverable, undeliverable, risky, and unknown categories. This allows users to understand the quality of each email address and make informed decisions about which addresses to keep, remove, or further investigate.
11 Feb 2022 - Kickbox
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