How to maintain a clean and healthy email list for a mid-size nonprofit?

Summary

Maintaining a clean and healthy email list for a mid-size nonprofit is crucial for sender reputation and deliverability, encompassing a multi-faceted approach. Core strategies include obtaining explicit permission and consent from subscribers with easy unsubscribe options, regular list scrubbing (removing inactive subscribers, correcting typos, and managing hard/soft bounces), active management of SMTP bounce codes, implementing soft suppression for non-engagers, avoiding spam traps through confirmed opt-in, segmenting based on engagement to enable targeted re-engagement campaigns, and utilizing email validation services like Kickbox or ZeroBounce for identifying invalid/risky addresses. Frequency of list cleaning should correlate with sending volume and activity. A Business Continuity Plan (BCP) and adherence to deliverability best practices round out a robust maintenance plan.

Key findings

  • Permission & Consent: Explicit permission and consent are fundamental, coupled with easy unsubscribe options.
  • Regular List Cleaning: Regularly scrub lists removing inactives, correcting errors and managing hard/soft bounces is essential.
  • Bounce Code Management: Actively manage SMTP bounce codes, immediately removing hard bounces.
  • Soft Suppression: Employ soft suppression to manage non-engagers automatically.
  • Spam Trap Avoidance: Avoid spam traps via confirmed opt-in procedures.
  • Segmentation & Re-engagement: Segment the list for targeted re-engagement campaigns to boost response.
  • Email Validation Services: Use services like Kickbox or ZeroBounce to identify invalid/risky addresses.
  • List Cleaning Frequency: Clean the list regularly based on volume and subscriber activity.

Key considerations

  • BCP Structure: Establish a solid Business Continuity Plan for email operations.
  • Engagement Threshold: Set a specific threshold for defining inactive subscribers (e.g., 6-12 months).
  • SMTP Error Codes: Understand and properly handle SMTP error codes.
  • Deliverability Impact: Monitor the deliverability impact of list maintenance and validation processes.
  • Compliance: Adhere to deliverability best practices like list-unsubscribe headers to maintain a positive sender reputation.

What email marketers say
10Marketer opinions

Maintaining a clean and healthy email list for a mid-size nonprofit involves several key strategies. Regular list cleaning is essential, including removing inactive subscribers, correcting typos, and managing bounces (both hard and soft). Segmentation based on engagement allows for targeted campaigns and the identification of inactive segments. Re-engagement campaigns can help win back subscribers before removal. Employing double opt-in ensures quality from the start and helps with compliance. Using email validation services can identify invalid addresses and spam traps. BCP structure is also important. List cleaning frequency should be based on sending volume and activity.

Key opinions

  • Regular Cleaning: Regularly clean your email list by removing inactive subscribers, correcting typos, and managing bounces (both hard and soft).
  • Segmentation: Segment your list based on engagement to target active users and identify inactive segments.
  • Re-engagement Campaigns: Implement re-engagement campaigns to win back inactive subscribers before removing them from your list.
  • Double Opt-In: Use double opt-in to ensure high-quality subscribers and help with compliance.
  • Email Validation: Utilize email validation services to identify invalid addresses, spam traps, and disposable emails.
  • List hygiene frequency: Clean list at least every 3-6 months, or more frequently if engagement rates are low.

Key considerations

  • BCP Structure: Ensure a robust Business Continuity Plan (BCP) is in place for email marketing operations.
  • Engagement Threshold: Establish a clear threshold for inactivity (e.g., 6-12 months) to determine when subscribers should be targeted for re-engagement or removal.
  • Hard vs. Soft Bounces: Actively manage hard and soft bounces, removing hard bounces immediately and monitoring soft bounces for potential issues.
  • Compliance: Ensure compliance with regulations like GDPR by obtaining explicit consent and providing easy unsubscribe options.
Marketer view

Email marketer from Validity suggests actively managing both hard and soft bounces. Remove hard bounces immediately and monitor soft bounces to determine if an address is permanently inactive. They suggest soft bounces can be an indication of a larger deliverability issue.

August 2023 - Validity
Marketer view

Email marketer from Mailchimp explains the importance of regular list cleaning, including removing inactive subscribers, correcting typos, and segmenting based on engagement. They also suggest using double opt-in to ensure subscriber quality from the start.

January 2025 - Mailchimp
Marketer view

Email marketer from Email Marketing Forum shares that using double opt-in is an excellent way to ensure the quality of your email list and prevent spam complaints. It also helps you comply with GDPR and other privacy regulations.

June 2023 - Email Marketing Forum
Marketer view

Email marketer from ZeroBounce explains that using an email validation service can help identify invalid, risky, and spam trap email addresses. They can also help you detect disposable email addresses, improving list quality. This protects you from a higher bounce rate.

June 2021 - ZeroBounce
Marketer view

Email marketer from Reddit advises setting a threshold for inactivity (e.g., not opening or clicking an email in 6-12 months) and then using a re-engagement campaign to try and win back these subscribers. If they don't respond, they should be removed from the list.

November 2022 - Reddit
Marketer view

Email marketer from HubSpot advises segmenting your list based on engagement and targeting only those segments that are active. They suggest re-engaging inactive subscribers with targeted campaigns before removing them, giving them a chance to opt back in.

February 2024 - HubSpot
Marketer view

Marketer from Email Geeks mentions that the BCP (Business Continuity Plan) structure is the important piece to put in place, and not just the size of the list.

March 2024 - Email Geeks
Marketer view

Email marketer from Reddit explains that the frequency of list cleaning depends on the sending volume and list activity. For a list of 40,000, they recommend cleaning at least every 3-6 months, or more frequently if engagement rates are low.

September 2024 - Reddit
Marketer view

Email marketer from Sendinblue shares that regularly cleaning your email list helps maintain a good sender reputation and improve deliverability. They recommend removing hard bounces, unsubscribes, and inactive subscribers to ensure you're only emailing engaged contacts.

September 2022 - Sendinblue
Marketer view

Email marketer from Lemlist shares that a targeted re-engagement email can revive subscribers on your email list. The email should have a clear call to action or offer an incentive to re-subscribe and to verify their email address is still valid and in use.

April 2021 - Lemlist

What the experts say
5Expert opinions

Maintaining a clean and healthy email list involves several expert-recommended strategies. Regularly scrubbing lists to remove inactive users, obtaining explicit consent, and providing easy unsubscribe options are fundamental. To identify and remove risky emails, consider using services like Kickbox to filter out low Sendex scores. Employ soft suppression to automatically stop emailing non-engagers while keeping them eligible to rejoin upon re-engagement. Utilize an ESP that properly handles bounce lists and diligently avoid spam traps by employing confirmed opt-in.

Key opinions

  • Permission & Consent: Acquiring explicit consent and providing easy unsubscribe options are critical for a healthy list.
  • Soft Suppression: Implementing soft suppression of non-engagers can automatically manage email frequency.
  • Bounce Handling: Using an ESP that properly handles bounce lists is essential.
  • Spam Trap Avoidance: Avoiding spam traps is crucial; confirmed opt-in helps prevent them.
  • Email Validation Services: Using services like Kickbox to filter low Sendex scores improves list quality.
  • Regular List Scrubbing: Regular list scrubbing helps to remove inactive or unengaged subscribers.

Key considerations

  • Manual Examination: Manually examining results after automated cleaning processes can further refine list quality.
  • Deliverability Impact: Monitor deliverability impact when revalidating and suppressing email addresses.
  • ESP Capabilities: Consider the capabilities of your ESP for soft suppression and bounce handling.
  • Sendex Cutoff: Choose a Sendex cutoff score based on your risk tolerance and list characteristics.
Expert view

Expert from Email Geeks recommends looking into ongoing soft suppression of non-engagers, which involves stopping emails after a certain period but keeping them eligible to receive emails again if they engage.

July 2022 - Email Geeks
Expert view

Expert from Word to the Wise emphasizes the importance of permission and consent in email marketing. She explains that acquiring explicit consent from subscribers and making it easy for them to unsubscribe are fundamental aspects of maintaining a healthy list. She also recommends regular list scrubbing to remove inactive or unengaged subscribers.

June 2021 - Word to the Wise
Expert view

Expert from Email Geeks suggests running non-responding emails through Kickbox, removing those with a low Sendex score, and manually examining the remaining results in Excel. He mentions revalidating a list of 2-3 million dormant addresses with a Sendex cutoff of .7, resulting in no deliverability impact.

July 2021 - Email Geeks
Expert view

Expert from Spam Resource highlights the importance of avoiding spam traps to maintain a clean and healthy email list. He explains that spam traps are email addresses that are used to identify spammers. Landing in a spam trap can severely damage your sender reputation and deliverability. They recommend using confirmed opt-in and regularly cleaning your list to remove old or inactive subscribers.

November 2021 - Spam Resource
Expert view

Expert from Email Geeks suggests using an ESP (Email Service Provider) that properly handles bounce lists.

January 2024 - Email Geeks

What the documentation says
5Technical articles

Maintaining a clean and healthy email list is crucial for sender reputation and deliverability. Core strategies include proper handling of SMTP bounce codes (immediately removing permanent failures and retrying temporary ones), using confirmed opt-in, providing easy unsubscribe options (list-unsubscribe headers, prompt honoring of requests), regular list cleaning, avoiding spam traps, and segmenting based on engagement. Good sender reputation is directly tied to sending emails to engaged subscribers and actively protecting from spam traps and unengaged addresses.

Key findings

  • Bounce Code Handling: Proper handling of SMTP bounce codes is essential for identifying invalid addresses. Remove 5xx errors immediately, retry 4xx errors.
  • Confirmed Opt-in: Using confirmed opt-in is critical to avoiding spam traps and maintaining a healthy sender reputation.
  • Easy Unsubscribe: Provide easy unsubscribe options, including list-unsubscribe headers, and honor unsubscribe requests promptly.
  • Regular List Cleaning: Regularly clean your list to remove inactive and invalid addresses.
  • Segmentation: Segment your list based on engagement, demographics, or purchase history to improve engagement rates.
  • Sender Reputation: Maintaining a good sender reputation is critical for email deliverability.

Key considerations

  • SMTP Error Codes: Understand and correctly implement handling for SMTP error codes.
  • Unsubscribe Process: The unsubscribe process should be simple and efficient for the subscriber.
  • Segmentation Strategy: Develop a clear strategy for list segmentation based on relevant data.
  • Compliance: Compliance with email marketing best practices is vital for protecting your sender reputation.
Technical article

Documentation from Google outlines the importance of maintaining a healthy sender reputation and avoiding spam traps. This includes using confirmed opt-in, providing easy unsubscribe options, and regularly cleaning your list to remove inactive or invalid addresses.

January 2024 - Google
Technical article

Documentation from Campaign Monitor suggests segmenting your list into specific groups based on engagement, demographics, or purchase history. This allows you to send more relevant emails and improve engagement rates, and also makes it easier to see which segments need work or even removal from your email marketing.

January 2023 - Campaign Monitor
Technical article

Documentation from Litmus share that maintaining a good sender reputation is critical for email deliverability. Cleaning your list regularly is one way to ensure you're only sending emails to engaged subscribers, protecting your reputation from being tarnished by spamtrap addresses and unengaged subscribers.

June 2022 - Litmus
Technical article

Documentation from RFC explains that handling SMTP bounce codes correctly is crucial for identifying invalid email addresses. Permanent failures (5xx errors) should be immediately removed from the list, while temporary failures (4xx errors) can be retried a few times before removal.

March 2023 - RFC 5321
Technical article

Documentation from Microsoft shares that following best practices such as using list-unsubscribe headers, honoring unsubscribe requests promptly, and monitoring bounce rates are essential for maintaining a clean list and good deliverability. They also recommend segmenting your list based on engagement to send more targeted emails.

November 2022 - Microsoft