Last updated
August 1, 2023

How to Clean your Email List

Elizabeth (Lizzie) Shipton

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Email marketing is the cornerstone of all online marketing efforts. Time again, it has been shown that email marketing is the most effective form of online marketing. Few other online marketing services' ROI compare to email marketing's ROI (return on investment.)

Not only that, email marketing automation is easy to do and will net you big returns with little time invested.

Why You Need an Email List

The engaged people on your mailing list are your most loyal customers, biggest fans, and most hardcore supporters. They will be the people most likely to buy your products and spread the word about your business. They should form the core of your marketing strategy.

Being in constant contact with your email list not only allows you to sell more products: it helps you get to know your customers so you can make more informed decisions about how to target them.

However, it's a hard fact of life that not everyone on your list will be engaged. Some users drift away, while others were never really interested in your product in the first place. Still more addresses on your list will be spam, fake, and inactive addresses.

In this article, we'll talk about why a clean email list is important, how to clean your email list using an email list cleaning service, look at some email service providers and email list cleaning services, and dive into the nitty gritty of email marketing.

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Why You Need to Clean Your Email List

It's important to keep your email list clean by removing inactive users, spam email addresses, and other things that can hurt engagement.

Good engagement equals good email deliverability, which lowers spam complaints, reduces your bounce rate, and prevents emails to new subscribers from ending up in their spam folders. For this reason, it's important to clean your email list regularly to keep engagement high.

Sender Reputation

When it comes to email marketing, the sender's reputation is everything. Sender reputation is the score that an Internet Service Provider (ISP) gives to an organization or individual that sends emails. It's a critical component of email deliverability. The better your sender's reputation, the more likely it is that an ISP will deliver your emails.

That's right: just because you send an email to a person on your email list, doesn't mean that email will necessarily arrive in their inbox. All email service providers check incoming mail to make sure it isn't spam or harmful to the recipient. If your email looks like spam, an email provider won't let it through.

So how can you improve your sender reputation and make sure your emails get through? The easiest and most effective way to do it is through engagement. Encourage your users to interact with your emails - either by clicking links or replying to the emails.

This is where it becomes crucially important to regularly clean your email list. A bloated list full of disengaged subscribers, fake email addresses, spam addresses, or undeliverable addresses will hurt your reputation, increase email bounces and spam complaints, and make it more likely that your emails will end up in the spam folder.

Monthly Subscriptions Start to Add Up

Most email delivery platforms require monthly subscriptions once you get over a certain number of subscribers, so you are most likely paying a monthly fee to keep a certain number of people on your list. If your list is full of people who don't engage with your email, it costs you money and returns no benefit.

How to Clean Your Email List

There are several components to cleaning an email list, and they don't all happen at the same time. Some can be done on a monthly or rotating schedule, while others can be automated or handled at sign-up.

Let's look at how to use your email marketing platform in tandem with one of the many available email list cleaning services to remove unengaged users, spam email addresses, duplicate email addresses, and invalid email addresses from your list.

Identify Low Engagement Subscribers

Your email communications tool probably provides a way to track low-engagement subscribers. Platforms like Mailerlite and Mailchimp allow you to filter subscribers based on certain parameters, such as the number of emails opened and the number of links clicked.

Most can also automatically identify which users have been least engaged in your last few email campaigns, or over a period of time. Look at the customer support page or documentation for your email marketing service to figure out how to identify these subscribers and create a group or segment to track them.

Send a Re-Engagement Campaign

Once you have identified your low-engagement email subscribers, the first thing you should do before simply removing them from your list is an attempt to re-engage them. Send an email to all users in that segment giving them the option to stay on the list or unsubscribe. You may want to entice them with a small freebie or giveaway to get them to stay.

Here's the thing though: if people unsubscribe from your list at this point, it's a good thing. It's better to have a smaller list of active subscribers than a bloated list full of invalid addresses and inactive email addresses that don't net you any returns.

Remove Inactive Subscribers

The next step can also be done through your email marketing platform. Once you've grouped and segmented all the inactive email addresses on your list, you can bulk unsubscribe them through your marketing platform's user-friendly interface.

Again, check the customer support page or customer support documentation for your specific provider on how to do this.

Unsubscribing vs Forgetting vs Deleting

There's a difference between unsubscribing a user, forgetting a user, and deleting a user, and you should know which is which before you decide how to handle a particular address.


Unsubscribing a user removes their address from the deliverable addresses on your list. You will no longer pay to have that address on your list, and you will no longer send emails to that address.

All their user data will still be in your database, and you can resubscribe them at any time. However, if you attempt to subscribe to them through normal channels (i.e. through a bulk subscriber upload or web form) they will not be subscribed. You have to do it manually through your email marketing platform.


Deleting a user removes their address from your list and also removes them from your account, however, their information is still retained in case they resubscribe at a later time.


Forgetting a user is GDPR-compliant. It removes a subscriber from your account, and within 30 days, all their information will be permanently deleted. Forgotten subscribers can still resubscribe at a later time, but they will be treated as completely new subscribers.

Check the documentation for your particular provider to learn how your platform handles unsubscribing, deleting, and forgetting users.

Remove Invalid Email Addresses

The final step in email list cleaning usually requires the assistance of an email list cleaning service. In this step, you identify all invalid emails: spam email addresses, bounced email addresses, fake emails, disposable emails, outdated contacts, etc.

These email addresses are different from the addresses of inactive subscribers. Inactive users have usually simply become disengaged, have moved on from your product, or have forgotten about you. Invalid emails, on the other hand, are often nothing more than fake addresses given by people who never wanted to be on your list in the first place.

The goal of this step is to be left with a contact list of only valid emails. There are many email list cleaning services and email list cleaning tools available online to help you do this. Let's take a quick look at how one of the easiest free email cleaning services - AbstractAPI's Free Email Verification API - works.

Download Your Email List as a CSV

Check your email marketing tool customer support page for instructions on how to do this. All email services provide an easy method for downloading your list into a CSV file that can be loaded into Excel or other spreadsheet software.

Upload the CSV to AbstractAPI's Bulk Uploader

Log in to the API dashboard and click "Bulk Upload (CSV.)" This will open an uploader where you can provide bulk addresses for validation and verification accuracy. The uploader will check all addresses on the list for the following things:

  • formatting and spelling
  • disposable addresses
  • MX records
  • SMTP records
  • role emails
  • catchall emails
  • free emails
  • deliverability

get the results

The results of the bulk addresses email validation will be emailed to you as a CSV. You will now know exactly which addresses on your list are valid and which are not.

Best Practices for Maintaining a Clean Email List

To keep your email list healthy, you should set up a regular schedule for cleaning and maintenance. At least once every six months, go through the list and remove all your inactive subscribers. Once a year or more, use email list cleaning services to remove inactive and invalid email addresses.

Some of the most important parts of maintaining a clean email list happen long before you do your scheduled maintenance. You can do a lot on sign-up to prevent an invalid email address from ever making it onto your list.

First, always use double opt-in in all your web forms. Double opt-in requires your users to click a confirmation button in an email that is sent to them before they are allowed onto your list. This one step alone dramatically cuts down the number of spam emails and invalid addresses that end up on your list.

Next, make sure your web forms use an email verification service or email verification API like AbstractAPI to validate email addresses before they are allowed to join your list. This type of service runs each email through a verification step and lets you know whether the address is valid or not.

Finally, make sure you treat your active and engaged subscribers well. They are the lifeblood of your online business, and they deserve to be treated with respect. Don't spam them. Don't be in constant contact without delivering something of quality.

Strive to build more meaningful relationships with your entire subscriber base by respecting their communication preferences and delivering high-quality content.


A solid email marketing strategy is the cornerstone of online marketing, and a healthy email list is one of the most important aspects of email marketing. It's important to clean your email list regularly using an email list cleaning service or the built-in methods provided by your marketing automation platform.

A clean list leads to better engagement rates, lower bounce rates, fewer spam complaints, more successful email marketing campaigns, tighter data security, and an email database that allows you to connect with your customers and sell more products.


How often should I clean my email list?

It's generally recommended to clean your email list at least once every six months to keep it up-to-date and remove any inactive or invalid email addresses. However, the frequency of cleaning also depends on the size of your list, the rate of new subscribers, and the engagement rates of your subscribers.

Can I clean my email list manually or do I need to use a cleaning service?

You can clean your email list manually if you have the time and resources to do so. However, a cleaning service can make the process more efficient and accurate, especially for large email lists. There are many third-party services that offer email list cleaning, such as NeverBounce, ZeroBounce, and BriteVerify.

What are some common mistakes to avoid when cleaning an email list?

Some common mistakes to avoid when cleaning an email list include not verifying email addresses, not segmenting your list, not removing inactive subscribers, and not asking for permission before sending emails. It's also important to avoid buying email lists and sending unsolicited emails, as these practices can damage your sender's reputation and lead to high bounce rates.

Will cleaning my email list improve my email deliverability rates?
Yes, cleaning your email list can improve your email deliverability rates. By removing invalid or inactive email addresses, you can reduce your bounce rates and improve your sender reputation. This, in turn, can help you avoid spam filters and increase the chances of your emails being delivered to your subscribers' inboxes.

How can I encourage engagement from my email subscribers to maintain a clean list?
To encourage engagement from your email subscribers, you can provide valuable content, personalize your emails, segment your list, and ask for feedback. You can also use incentives, such as discounts, gift certificates or freebies, to encourage subscribers to engage with your emails. Additionally, it's important to regularly monitor your engagement rates and remove inactive subscribers to maintain a clean and engaged email list.

Elizabeth (Lizzie) Shipton
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