Email List Hygiene: 5 Tips to Keep Your Lists Squeaky Clean

March 23, 2024
Written by
Jesse Sumrak
Opinions expressed by Twilio contributors are their own

Email List Hygiene: 5 Tips to Keep Your Lists Squeaky Clean

Email list hygiene is like normal hygiene—it should be a regular part of your routine. Growing your subscriber list is a critical element of a strong email marketing program. But it’s equally important to complement those efforts with regular email list cleaning.

No one wants to lose subscribers, but unengaged recipients can hurt your email program. If many recipients delete your emails without opening them or, even worse, mark them as spam, this could signal to inbox providers that you’re sending unwanted content. This, in turn, could impact your deliverability.  

That’s why email list hygiene is vital to a healthy email program. This post will explain how to keep your email lists squeaky clean with proper scrubbing and cleaning. 

What is email list cleaning? 

Email list cleaning, also known as scrubbing, is the process of removing inactive, bounced, and other unengaged email addresses from your list. This ensures that you only send emails to people who want to read them. Proper email list hygiene will help you:

  • Improve your sender reputationHigh bounce rates and low engagement can negatively affect your sender reputation, leading ISPs to flag your emails as spam.
  • Boost your engagement ratesBy removing uninterested or inactive subscribers, you're left with a more engaged audience. This improves open and click-through rates and provides a more accurate measure of how well your content resonates with your audience.
  • Reduce the chances of landing in the spam folder or on an email deny listSending emails to disinterested parties increases the likelihood of your messages being marked as spam. This can harm your sender reputation over time.
  • Lower your email costs: Keeping your list clean helps you avoid wasting resources on unproductive leads, allowing you to allocate your budget more effectively towards engaging with genuinely interested subscribers.

While the thought of reducing your subscriber count might be unsettling, the quality of your list is far more important than quantity. A smaller, more engaged audience is much more valuable, leading to higher conversion rates and a better ROI for your email marketing campaigns. 

Remember, email list cleaning should be an ongoing part of your email marketing strategy, not a one-time event.

Email list hygiene: How to clean an email list

Now let’s get into the nitty gritty of when and how to clean an email list. Use these tips to keep your lists fresh. 

1. Define how often you need to clean up your list

How frequently you scrub your email list will depend on certain aspects of your program. Generally, we recommend cleaning your list every six months. But larger email programs (100,000+ subscribers) may benefit from more frequent list cleaning, while smaller ones (under 1,000 subscribers) may not require the same level of rigor.

Regularly reviewing your engagement metrics will give you a clear picture of how healthy your list is overall, and this can help you decide how often you need to address list cleaning.

Whatever frequency you choose, stick to your cadence. However, you can revisit your cleaning frequency each year and determine if you need to change your approach. 

Bonus tip: Don’t purchase lists from third-party vendors… or anybody ever. While you may reap some immediate, short-term benefits, the majority of the addresses on these lists won’t earn you much value. And you may even find yourself on a deny list as a result. 

Recipients from a purchased list are more likely to hit the spam button because they never signed up for your email program. This will only hurt your sender reputation. For more reasons why you should never purchase an email list and some tips on how to grow your list organically, check out 3 Reasons You Shouldn’t Buy Email Lists.

2. Remove role accounts

Role accounts are email addresses that represent a group or alias—think @support, @info, etc. These emails do not represent individuals, and, as a result, no one checks these inboxes very often. So if you have role accounts on your lists, engagement from these will typically be low. 

Because these types of accounts are shared, different people who check them will have different levels of engagement with your emails. For example, say there’s an employee who regularly checks the alias inbox and reads your emails but they leave the organization. Whoever steps into that role next might not find your messages valuable, and they may decide to mark your emails as spam.

Pro tip: The Twilio SendGrid Email Validation API can check for role emails and automatically remove them from your list.

3. Remove bounced and invalid emails

Bounces refer to emails that don’t get delivered because the email address is invalid. This could be because the recipient typed it incorrectly when they subscribed to the email list, or it’s a company email address that no longer exists. 

You don’t want to continuously send emails to invalid addresses because this can negatively impact your metrics, especially your delivery rates. Experts recommend that you keep your bounce rate under 0.5%. Anything above that could hurt your sender reputation. 

Most email service providers (ESPs) automatically remove hard bounces after two failed attempts to deliver emails. But in some cases, invalid email addresses are harder to identify. 

The Twilio SendGrid Email Validation API helps reduce hard bounces by showing you the email addresses that are likely to cause these. You can then keep an eye on these addresses and remove them from your list if the emails bounce.

4. Address unengaged recipients

Unengaged recipients can sting the most to remove. But don’t take low engagement personally. Think of how many emails you’ve signed up for but never get around to opening and reading!

Although providing an unsubscribe link in your emails is required (by law and by all reputable ESPs), a lot of times, people may not get around to unsubscribing. If a few months go by and a recipient hasn’t opened any of your emails, it’s time to address the issue. 

First, try a re-engagement campaign to gauge their interest in receiving your communications. This type of campaign gives recipients the opportunity to update their email preferences. In the best case scenario, the recipient says they still want to hear from, but maybe less frequently. Or maybe they decide to unsubscribe. Either way, it will help your email list.

Some recipients may not respond to your re-engagement campaign. This is your sign that it’s time to remove them from your list. It may hurt to see them go, but it’s for the benefit of your email program. Inbox providers look at engagement metrics such as opens to determine delivery. If they see that you keep emailing unengaged recipients, this could impact your sender reputation. 

5. Confirm email subscriptions

There are several ways to confirm email addresses upon signup. We recommend providing a double opt-in method because it’s the best way to ensure that the subscriber truly wants your emails.

Double opt-in signup requires the subscriber to enter their email address on your signup form and then confirm that they meant to do so, usually through a confirmation email containing a link that they need to follow to finish registration.

This method demands a little more work on the user’s end, but it’s worth it for both the sender and recipient because it helps keep invalid email addresses off your list and reduces the chances of the recipient getting unwanted emails. 

Clean vs scrub email list: what's the difference?

The terms "clean" and "scrub" in the context of email lists are often used interchangeably in email marketing, but they can imply slightly different processes. Both are aimed at improving the health and performance of your email list, yet they focus on different aspects of maintenance.

Understanding these nuances can help you better manage your email marketing strategy.

Email list cleaning

Email list cleaning generally refers to the simpler process of removing invalid, non-existent, or bounced email addresses from your list. It’s about ensuring that the emails you send have the potential to reach someone on the other end.

Cleaning helps reduce bounce rates and protects your sender reputation by ensuring you're not sending emails to addresses that are no longer active or were incorrect from the start.

Key aspects of email list cleaning include:

  • Removing email addresses that hard bounce.
  • Eliminating obviously fake email addresses (e.g.,
  • Purging contacts that have unsubscribed from your list.

Email list scrubbing

Email list scrubbing goes a step further by not only removing non-functional or harmful addresses but also segmenting or removing subscribers who are unengaged or unlikely to convert. This process involves analyzing subscriber behavior and engagement levels over time to identify those who do not open or interact with your emails.

Key aspects of email list scrubbing include:

  • Identifying and segmenting inactive subscribers for targeted re-engagement campaigns.
  • Removing subscribers who consistently fail to engage with your content after a set period or after re-engagement attempts.
  • Analyzing subscriber engagement patterns to improve targeting and content relevance.

Keep your email lists clean with Twilio SendGrid

Cleaning your email lists on a regular basis will improve your engagement metrics, sender reputation, and deliverability rates. And Twilio SendGrid makes the process easier with list management tools that help you track engagement and ensure you send emails that recipients want. 

We take email list hygiene seriously.

If you’re ready to dive into more delivery best practices, download our free Email Deliverability Guide. It contains everything you need to know about sender reputation, user experience, privacy and compliance, and more. 

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