List Cleaning: Why It Is Important and How To Maintain a Clean List

Great deliverability is the key to any successful email marketing campaign. It doesn’t matter how much effort you have put into the campaign, what you are promoting, or how great your content is, if your emails can’t reach your customer’s inbox, you won’t see results.

One of the most common and easiest ways to improve both deliverability and engagement is through regular list cleaning.


What is list cleaning?

List cleaning is removing inactive, unengaged, or questionable contacts from your email list.


Why is list cleaning important?

Today’s email service providers (ESP’s) have complicated and constantly changing algorithms to determine how, when, and where your email is delivered. Your sending reputation has a heavy impact on this algorithm.

Sending to only engaged and active contacts who interact with (read or click) your emails is crucial to having a good reputation.


What if my list is not clean?

Apart from having a poor reputation you run the risk of: lower deliverability, higher bounce rates, increased spam complaints, hitting spam traps, getting put on blacklists, increased sending costs through bloated data, and decreased ROI on your marketing efforts.

How do I start?

The best practice is to start at the source. Implementing a verification service on any sign-up form, like reCAPTCHA, will weed out many bots from infiltrating your list.  This can be added on any Mautic form by selecting the ‘reCAPTCHA’ field when creating a form.  For details on how to setup this plugin, please click here.



If you are importing contacts directly into Mautic, they should be run through a list cleaning service prior to the upload. There are popular services like kickbox and NeverBounce where lists can be uploaded (.csv files) and cleaned, prior to importing into Mautic.


How do I maintain a clean list?

As regular maintenance, you should run your contacts through a list cleaning service every 3-4 months. However, if you start to see a major dip in engagement, or increase in bounce rates, the list should be cleaned immediately.

Please keep an eye on these important statistics through Mautic’s reporting features. Seeing sharps dips in engagement like the chart below is a strong indicator that the list should be cleaned:



Also, removing contacts from your segments who are no longer engaging with your content is a good idea to ensure your list is clean. Mautic has a number of segment filters including: date last active, email read date, and clicked date, to help filter out contacts who are no longer interacting with your communications.




If you have any questions on list cleaning or deliverability best practices please reach your to your Mautic Customer Success Manager or Also, please note that if you do not follow the recommended list cleaning practices, your account may be suspended.