How to use email validation to clean your list

Email validation is a best practice that helps improve email deliverability and protect your sender’s reputation, so it’s important to implement it properly. To get the most out of email validation, you should use an email verification tool that automates the process and gives you access to actionable insights into your list. In this post, we’ll explain everything you need to know about validating emails, including why you should do it in the first place and what kind of results you can expect when you start using one.

Why do email validation?

Email validation is a way to clean your email list, which can help you improve email deliverability and open rates.

When you send an email campaign to someone who doesn’t exist or no longer has access to the mailbox he or she used, the recipient will never see it. If a recipient’s inbox is full when an email arrives, it’s considered a bounce and won’t be delivered.

Additionally, if someone has a different name from the one you have in your database (e.g., “John” vs. “John Smith”), that person may receive an undeliverable message because your system isn’t recognizing him/her by their new name.

What you need to validate your emails

To get started with email validation, you’ll need a list of email addresses and a program to perform the validation. You can check your deliverability with services like MailTester, Email on Acid, Litmus and

What are invalid emails?

There are two main types of invalid emails:

  • Email addresses with invalid syntax, meaning there is a missing or incorrect domain, username, and/or password
  • Emails with an invalid format (e.g., the address isn’t formatted correctly)

What are risky emails?

Before you can begin to clean your list, it’s important to understand what types of email addresses are considered “risky” and why they need to be removed. There are three main categories:

  • Free email addresses (e.g., yahoo or hotmail)
  • Email addresses that have been abandoned or no longer belong to the person who subscribed

These may appear harmless at first glance; however, these risky emails can be used by spammers who want to send spam messages to all of your subscribers on your behalf, which could result in serious consequences such as blacklisting by ISPs or webmail providers (Gmail). In addition, they can also be used by cyber criminals who want access to personal information that you may store in your CRM system such as first name, last name and email address.

What are disposable or catch-all emails?

Catch-all emails are often used when a business doesn’t have a dedicated email account for each employee. For example, if someone wants to contact your company about customer service, they could send an email to [email protected] . If that inbox isn’t monitored by anyone, the message would be sent to all employees in the company as an automated response from your IT department saying that you’ve received the message and will get back to them at their earliest convenience.

These accounts can also be used by spammers who want to send out spam emails without being caught by spam filters or security software like Google’s reCaptcha. The unfortunate reality is that catch-all emails can be hard for us humans (or even robots) who aren’t familiar with every single person at every single company we sign up for looking up on our behalf!

How to check the validity of an email address

To check the validity of an email address, you can use a tool like MxToolbox or Email on Acid. Both sites will let you check a series of domains at once—for example, [email protected], [email protected], [email protected]—and report back whether they’re valid.

If there’s no information on these sites that indicates if an email address is valid, try Googling it: if others are using it, chances are good that it works! If all else fails and you have access to the webmaster tools for your domain provider (e.g., Gmail), try signing into their interface and searching for invalid addresses in their bulk contact list section (this is often under “Users”).

Remove invalid addresses and improve email deliverability.

When you remove invalid emails from your list, you’ll improve both your email deliverability rate and open rates.

In addition, by reducing the number of invalid emails on your list, you can increase the number of clicks that come in from each email campaign without having to pay more for clicks.

If you’re using an ESP like MailChimp or ConstantContact, this can be done automatically through their software with a simple click.


Email validation is a powerful tool to keep your email marketing campaigns running smoothly. It helps you clean your list and improve your deliverability while also identifying addresses that may be risky or disposable. While there are many ways to check the validity of an email address, we recommend using at least two different methods: one free tool and one paid service (like Return Path). In this blog post, we covered how these services work as well as some best practices for using them together with other data sources like Gmail’s Advanced tab. However, it definitely helps if you make sure not to receive too much spam in the first place. Hence, you could implement an IP data API that checks for bots or programmatic behavior before the email address is even submitted to your database. For this, services like or can be used.

Interesting Related Article: “5 Ways How Email Validation Can Help Boost Marketing Campaigns