Email List Hygiene and Effective Segmentation

What is an email list?

Suppose you are a customer buying a shirt from your favorite online shop. At checkout, you decide to check the box that subscribes you to the store’s email newsletters and exclusive discounts. By doing so, you subscribed yourself to that company’s email list.

“An email list is the cumulation of email contacts, collected by businesses to market their products and/or services.” (Inboxroad) An email list is central to your email marketing and successful email marketing can generate a higher ROI in comparison to other marketing approaches.

In a previous post, we discussed the ways that you can organically and ethically grow your email contact list. Without an effective contact list, your marketing efforts would be wasted and possibly harmful to your sender reputation.

An example of an ineffective email list is one with many invalid email addresses, unresponsive contacts and users who did not subscribe to your list. This type of list will ultimately set you up for bounced emails, spam complaints and email rejections.

List Hygiene

List hygiene is something that you should dedicate time for around every six months. So, how do you maintain good email list hygiene and avoid the previously mentioned risks? The following are a few best practices to abide by:

1. Rid your list of all inactive subscribers

If an email service provider (ESP) notices that your emails have a low open and click rate, they might decide to send those emails to the junk box. Before deleting inactive addresses, you could also send these subscribers re-engagement emails should they still find interest in being included in your marketing emails.

2. Delete any contacts that did not give explicit permission to email them

Making sure your list is filled with contacts that opted-in to your emails is crucial to ethical email marketing. Some marketers buy their email lists, but doing so risks being prohibited from sending emails and “breaching GDPR rules.” (Inboxroad) Unsolicited emails can also lead to a higher number of spam complaints.

3. Send the right messages to the right audiences

Adding a touch of personalization can lead to higher engagement and more clicks. If you target your messages based on any number of subscriber characteristics (location, interests, purchase history), you should be sure that the right messages are going to the right subscriber list.


This is where segmentation comes in. In order for you to send targeted messages to different subscribers, it is useful to segment your email lists.

Segmentation is the act of dividing your subscribers into various groups or segments based on shared characteristics, customer histories, interests and more. Marketers enjoy email list segmentation because of its value in personalized communication and individualized customer experiences.

There are several ways for marketers to segment their lists:

  • Location-based: this is one of the most common ways of segmenting your subscribers. By dividing up your contacts based on their geography, you can inform them of location-specific deals, events or products.
  • Content-based: this can be related to data collected on the and interest your customers show in your website and products.
  • B2B and Specialization-base: these lists would be divided based on the different businesses you work with, or the various specialities you are addressing – such as marketing specialists or customer success managers.
  • User behaviour-based: this segmentation is based on the actions and behaviours of contacts on your pages, the length of time they spend viewing a product, the frequency of their visits, etc.
  • Recency, frequency, monetary value (RFM) – this type of segmentation is based on when a customer’s most recent purchase was, the amount of purchases they made, and the amount of money they spent on their purchases altogether, respectively.

List Building

In this post, we covered what email lists are, list hygiene best practices and what email segmentation is. When you get rid of inactive email addresses and clean up your lists, it becomes important to grow your lists with active, engaged subscribers. You can grow your list by making sign-ups easy, creating subscription landing pages, motivating subscriptions, creating referral campaigns and offering a section on customer reviews. You can read more about these tips here.