Keeping Your Email Lists Squeaky Clean

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Email Marketing Data Cleansing Tools - Maxemail| Emailcenter

One practice we stand by is permission-based email marketing, which means we’re extremely good at making sure our clients use their own email lists when sending emails via Maxemail. Data cleansing (or data cleaning) is often a time-consuming process, so it is important for us to have the tools and information in place to help users maintain a healthy email list.

Where Do I Start With Data Cleansing?

We get asked this question a lot, and although we don’t offer a data cleansing service we can definitely provide the following advice on how Maxemail (our email marketing platform) works to clean your email list upon every send, and what you can do to manage your subscribers.

Firstly, Know that Maxemail Manages…

Data Consistency

When people subscribe to your emails they won’t think about how you want their information, so you may see a mix of lowercase and uppercase across your email list. For consistency, Maxemail will allow you to format your data in uppercase, lowercase or title case.

Duplicate Email Addresses

No doubt you’ll get people subscribing to your email list more than once. This will cause duplications and you don’t want to be sending multiple copies of the same email to the same person. Maxemail will remove duplicate email addresses for you to prevent this from happening.

Bounced Email Addresses

Maxemail will identify invalid and unresponsive emails addresses that have bounced back and automatically add them to your master suppression list. This process will prevent future emails being sent and is done to protect your sender reputation. You can easily view your master bounce list from the dashboard and monitor how many temporary and permanent bounces are received off the back of each campaign.


You should always include an unsubscribe link in your email, it’s the law. Anyone who unsubscribes from your emails sent via Maxemail will be automatically added to your master suppression list. You can also see the email addresses that have unsubscribed from individual campaigns, and you should monitor this closely with all other metrics to assess how people are reacting to your messages.

Spam Complaints

Even though you will have gained consent to send marketing messages, there will still be a small percentage of people that forget they ever signed up to your emails. Modern email clients make it very easy for a recipient to mark an email as junk, even if this is not the case. The recipient may not immediately recognise the sender or may use the junk button in lieu of the unsubscribe link.

Failing to remove these subscribers immediately can increase the chance of them complaining on the next email sent, which can result in your emails landing in the junk folder. This can damage your sender reputation if enough people complain.

Maxemail will gather spam complaints as feedback from your individual campaigns and automatically put a stop on future attempts to these email addresses. These are listed as “Feedback Unsubscribes” in the campaign reporting tab.

Here’s What You Can Do…

Use a Double Opt-in Subscription Process

To prevent invalid email addresses filtering through to your email list, we strongly recommend using a double opt-in subscription process. By doing so, you’re asking the subscriber to confirm their subscription by logging in and validating the email address from their inbox.

This will give you that additional level of security as there will be a percentage of people who mistype their email address, and it will also help you to filter out spambots that enter your website and input data into random forms.

Use a Preference Centre

By allowing your subscribers to update their preferences you can ask them to keep you up to date with any changes, which will help you to keep your email list clean. For example, if they’ve input their name incorrectly or their email preferences change then they can amend this themselves.

Re-engage with Inactive Subscribers

Don’t waste time and money on sending emails to those who have not opened in a while. You can easily identify and segment these subscribers, add them to your master suppression list or run a separate campaign to try and reconnect.

A popular tactic is to tease them with an exclusive offer to see if they open your email. Try to re-engage them, and if that fails you can simply ask them if they wish to stay subscribed to your list. By doing so, you can identify those who no longer wish to receive emails from you and improve results if you concentrate on those who are engaged.

A word of warning, even though a customer is not opening your emails simply seeing your brand in the inbox has an impact. When running a controlled test, you may see a percentage of customers placing orders on your website that are not engaging with marketing emails.

Watch Out for Old Data Lists

Data that hasn’t been used for a while won’t have been continually cleaned upon every email send, so there’s a high chance this will contain old and invalid email addresses. Email addresses that have not existed for a period of time can get turned into spam traps, leading to you being blocked if you send emails to them. Unsubscribe and complaint rates can also be higher from old email lists, so it’s best to test in very small batches and measure the response.

Take Data When Moving Email Service Provider

One mistake email marketers often make is forgetting to take their bounce data with them when moving from one emails service provider to the other. On the first send, problems can be encountered if trying to send emails to email addresses that have previously bounced, which can affect deliverability and even result in blocking.

If you’re thinking of moving to Maxemail, we’ll be asking about your master bounce list!

About Nicola Faulkner

Senior Marketing Executive at Emailcenter UK Limited.