The Email List Decay Report for 2024

See how fast your email list goes bad – and what you can do to keep it healthy

At least a quarter of your email database may have degraded in the past year. ZeroBounce’s Email List Decay Report for 2024 unveils exclusive, never-before-published data to help you get more out of your email list.

Building an email list is one of the smartest things you can do for your business. With more than four billion users worldwide, email is the lifeblood of transactional communication. As a marketing channel, it allows for unparalleled ROI opportunities. There are even million-dollar businesses run exclusively through email.

But for email marketing to work, great content can only make an impact if you actually connect with your prospects. So first, you need a healthy, valid email list. And much like your business and customer base, email lists are ever-changing.

A contact valid yesterday could be invalid today if that person left their job. In the past few years, pandemic-related layoffs, business shut-downs and The Great Resignation have caused email data to decay even faster. People also switch to different email services and abandon their old addresses. We’ve all done it at least once.

Email list management thus becomes an ongoing purpose.

How does email list decay affect the health of your email list over time? Does obsolete data lower your email deliverability? What can you do to always keep your email list fresh?

The ZeroBounce Email List Decay Report for 2024 answers these questions – and more. In this study, we bring exclusive insights into the dynamic lifecycle of email lists. Use this data to build your database the right way, increase email list engagement and hit your marketing goals in 2024.

The Email List Decay Report for 2024: Average email list health statistics

ZeroBounce validates billions of email addresses yearly. We learn a lot from the data we process – and now, we share our findings with you.

To create this report, we looked at all the email data we verified between January and December 2023. Then, we analyzed the overall email validity for previous years and compared these two data sets to understand better how email lists degrade.

Our customers range from solo business owners to behemoths like Amazon, Disney and Netflix, so the findings below reflect statistics across various business sizes and industries.

Email validation results for bulk and real-time verifications

ZeroBounce verifies emails in bulk and in real time, through the email validation API. Next, let’s break down the results from both email verification methods.

Bulk email validation results – identified when users uploaded existing email lists:

Real-time email validation results – detected by the ZeroBounce API:

2023 email list decay by the numbers

Percentages paint a broad picture of how much email lists degrade in a year. But let’s look at the actual numbers to get an even better idea of the amount of bad data lurking in email lists.

In 2023, ZeroBounce identified:

Email validity between 2021 and 2024

In 2023, ZeroBounce found that at least 25.74% of all emails it checked were invalid and risky. Was that percentage higher or lower in previous years?

We tracked that data, and here’s what we found:

Email list decay in 2022: a total of 22.71% of all emails were risky

Email list decay in 2021: a total of 23.16% of all emails were risky:

Our data shows that email lists contained more outdated contacts in 2021 than in 2022. The higher percentage from 2021 could have been a residual effect of pandemic-related layoffs and businesses closing. Another significant contribution to data decay was “The Great Resignation” trend that started in early 2021. A year later, overall email validity improved by 0.45%.

How often should you clean your email list?

To keep email decay at bay and protect your sender reputation, clean your email list at least once a quarter. If your database grows quickly, run it through our email verifier every month.

Want to take a step further to preserve your email list hygiene? Connect our API to your CRM and any platforms you use to gather leads. Once set up, the API checks every new sign-up in real time so that no invalid and fake emails can make it to your list.

Related: Learn about the value of email validation

Frequently asked questions

Email decay reflects the degradation of email data in email lists. Data decays due to shifts in the workplace, people using fake email addresses or abandoning their old email accounts. Email decay causes poor email list engagement and low email deliverability.

At least 25.74% of an email list decays every year. Email lists degrade at such a fast pace because businesses close, employees change jobs and email providers, or abandon their old email addresses. Companies looking to improve their inbox reach and email list engagement need to verify email addresses periodically.

You can prevent email decay by validating your email database regularly. Removing invalid and obsolete email addresses from your email list helps you reduce bounces, avoid the spam folder and boost email list engagement

List decay refers to the percentage of email addresses in an email list that become invalid or dormant over time. Some email addresses go bad, while others are abandoned, causing your email metrics to drop. Poor email list engagement affects email deliverability, so it’s best to prevent list decay by cleaning your email database regularly.

You can measure email deliverability by testing your email campaigns before you send them to your audience. Inbox testing tools help you determine if your email will land in the inbox, go to spam or not get delivered.

A good email open rate depends on your industry. The benchmark for email open rates, for all industries, is between 21% and 22%.

Email validity measures whether an email address is valid or not. An email verification service runs several checks to determine email validity. Using a valid email list is vital to building a good sender reputation and landing in the inbox.

An email list cleaning service allows you to validate an email database in bulk or in real time, to restore email list decay and improve email list hygiene. Email list cleaning services can determine whether an email address is valid and active. It helps to prevent bounces and boost email deliverability.

You should clean your email list at least once a quarter. Email lists decay at an average rate of 25% per year, causing companies email deliverability issues and preventing them from reaching their customers. To avoid such issues, have a consistent email list management system, use proper email list segmentation and send emails regularly.

The best verification and cleaning starts with ZeroBounce

  • Get 100 free monthly email verifications