Clean email list: tips, benefits, and example

Feb 6, 2025

A clean and responsive email list, every marketer’s dream? Yes, but here’s the thing: when our daily workload is packed with projects, ideas, and event-driven campaigns, cleaning our email database is often the last thing on our minds. However, neglecting this maintenance has real consequences on your email performance: a damaged sender reputation, declining deliverability, increased complaints, and lower profitability from email campaigns… Agathe, email deliverability expert at Mindbaz, explains how to maintain your email list so your newsletters land in the inbox.

Use an email cleaning solution

What does an email list cleaning solution do?

At Mindbaz, we always recommend using an email cleaning solution before anything else.

Depending on the solution, it can help remove:

  • Bounces
  • Suspicious addresses
  • Professional email addresses

This allows you to protect the sending reputation of your fresh IPs and associated domain by avoiding excessive hard bounces.

The risks of dangerous emails

Emails flagged by these cleaning solutions can be risky for your campaigns for several reasons:

❌ Hard bounces: the definitive error

A hard bounce is a permanent error message returned by the Mailbox Service Provider.

It indicates that the recipient no longer exists due to an invalid or obsolete email address.

A high hard bounce rate is a sign that your email list has not been engaged recently.

As a result, ISPs will quickly block your emails, damaging your sender reputation.

Hard bounces should be immediately identified and filtered out as soon as they occur.

🪤 Spamtraps: the trap to avoid

A spamtrap is an email address designed to catch senders who fail to follow best practices in email collection or database management.

🔗 Discover the email and deliverability glossary

Avoid getting blacklisted by major institutions like SpamHaus by regularly cleaning your email lists.

A collection tip that applies at any stage of the lifecycle: Use captchas or a minimum level of security within your sign-up forms! This helps limit bot-generated email sign-ups and the issues that come with them. Implementing a double opt-in process strengthens the quality of your email list.

↩️ Bounces: the visible sign of a poorly maintained email list

They are the most visible indicator of database hygiene for ISPs and anti-spam filters. A soft bounce is a temporary error message. It can be caused by:
  • A full inbox
  • The recipient’s server being unavailable
  • An email that is too large

📌 Unsubscribes: an important data point to keep

Unsubscribes must be processed within 48 to 72 hours and should always be retained in memory. Ideally, the unsubscription should be effective immediately. Re-engaging unsubscribed users for sales events like Black Friday is a practice to avoid at all costs. This is illegal and can have serious consequences on your email ecosystem’s reputation and the deliverability of your campaigns.

API and email list hygiene

If all your data flows through API connections, ensure that all integrations between collection sites, data updates, analytics platforms, and email routers are properly configured and communicating seamlessly.

The goal is to prevent data loss, which could impact your email performance and sender reputation.

Which solutions should you use?

ZeroBounce (United States)

ZeroBounce is a U.S.-based solution specializing in email validation, helping identify invalid addresses, spam traps, and abuse emails. The tool also provides detailed reports to optimize email deliverability.

A filter for dangerous emails: SafeSend

SafeSend is a Mindbaz feature that automatically filters invalid addresses, bots, and high-risk contacts.

Reduce your hard bounces and spam complaints while gaining better insights into your email statistics by excluding non-human interactions. SafeSend activates quickly for more efficient campaigns.

No more manual blacklists—this is a simple and effective solution to optimize your email reputation.

🔗 Learn more about SafeSend email filtering

CaptainVerify

CaptainVerify is a French-based solution that cleans and verifies email lists by eliminating invalid addresses, duplicates, and spam traps. Based in France, it ensures full compliance with GDPR while offering an intuitive interface and fast results.

The benefits of a clean email database

A regularly maintained database helps:
  • reduce the risk of blacklisting
  • maintain high-quality data
  • improve email deliverability
  • protect your domain’s reputation
  • maintain a strong sender reputation
  • reduce complaints
Beyond improving your email statistics, maintaining a clean database also provides deeper insights into your results. If an issue arises with an ISP or a blacklist, you’ll be able to identify potential causes more easily, resolve them, and request delisting.

Database maintenance: reactivating inactive contacts

Inactivity and engagement

Maintaining a clean email database also means managing inactive contacts—an essential task.

Engagement has become increasingly important in ISP filtering, particularly in the U.S., but also globally.

For your messages to land in the inbox, they need to be expected by recipients, generate opens and clicks, and have a reasonable reading time, among other factors.

Inactivity and deliverability

To improve deliverability, consider these solutions:

  • Gradually reintegrate inactive contacts into your regular email sends in small proportions
  • Run a dedicated reactivation campaign cycle

First, select inactive addresses that have been unresponsive for no more than six months.

If there are no clicks or opens after three to four sends, permanently remove the inactive addresses.

🔗 Understanding email deliverability: the ultimate free guide, no download required

This is a crucial step that will help you maintain a strong sender reputation, significantly increasing your chances of landing in the inbox. It is also THE key factor in keeping your email database up to date, high-quality, and effective. Even if implementing a dedicated strategy may seem tedious, don’t underestimate its positive impact on your email campaigns. 📕 At Mindbaz, we’ve written a comprehensive ebook on this topic. It includes practical advice and real-world examples to help you adapt your sending strategy effectively.

Switching email routers: best practices for your database

Managing unsubscribes

If you’ve paused your activity or are switching email routers, don’t overlook the importance of recovering your unsubscribes and all your key statistics!

Tracking unsubscribes is essential to:

  • avoid complaints
  • protect your sender reputation
  • maintain your brand image

Segmenting your database

Your email statistics are the foundation for creating relevant target groups and maintaining a high-quality sender reputation.

Contact Mindbaz team to talk emailing and deliverability