• by Ray Schultz , Columnist, February 12, 2025

Email databases degrade at a rate of at least 28% per year — and they’re getting worse, according to the Email Decay Report for 2025 from ZeroBounce. 

The decay rate grew as follows over the past several years:

• 2021 — 23% 
• 2022 — 22% 
• 2023 — 25% 
• 2024 — 28% 

ZeroBounce detected 2.5 billion invalid email addresses in 2024. Only 62% of the verified addresses were valid and safe for sending, although that was a 1.9% improvement.

In addition, the company identified over 5 million disposable emails, those given by people to avoid handing out their real email addresses. And the company’s email verification API detected email verification API detected over 10 million typos.

"Reaching the inbox has become increasingly difficult for companies across all industries, and poor-quality data is the biggest culprit," says ZeroBounce founder and CEO Liviu Tanase. "Invalid emails bounce and taint sender reputation, causing emails to land in spam or get blocked altogether.” 

Here is the breakdown of the overall list decay identified by ZeroBounce software:  

• Valid emails — 59%
• Invalid emails — 24.34%
• Catch-all emails — 10.80%
• Abuse emails (reported by known complainers) — 1.59%
• Do-not mail addresses (poor quality and risky contacts) — 1.74%
• Spam traps (Set up by internet service providers and blacklist providers) — 0.01% 

What should you do? 

"Clearing out obsolete data makes email lists more engaged and likely to drive sales. While many companies chase larger lists, those that prioritize clean, high-quality data will see better performance and a stronger ROI," says Brian Minick, chief operating officer, ZeroBounce.