Email Verifier - Validate and Clean email addresses

Email Verifier are services that help you to clean your email lists from invalid email addresses (bounces), disposable email addresses, catch-all email addresses and spam traps without sending emails.

Use our free validation service CampaignKit for single email addresses to test such a service and learn how it can help you. Sign Up to get access to bulk email validation to clean your entire email list.

The benefit of email validation services is the fact, that you can clean your email lists without actually sending emails to your audience.

Common best practice in email marketing is to segment your audience based on engagement and filter our emails with very low engagement to reduce the risk of getting flagged as spam or even hitting spam traps by recycled email addresses.  

Why is email validation relevant?

Let's first distinguish between the different types of emails that reach us today:

  • Transactional emails from SaaS services like email verification for a sign up, password reset, emails about changes to the terms of services and other service relevant emails
  • Informational or newsletter emails are sent to an audience who subscribed to an email list. This includes emails such as product or company updates.
  • Cold outreach emails are usually used in sales. Depending on the country you can send emails to people without an opt-in. Usually used in b2b sales, by curating a list of possible leads.

Look at the first type of emails send by SaaS services. You offer free accounts and have a high number of possible emails in your system.

You want to prevent users from signing up with disposable emails or putting spam trap emails in your signup form that will blacklist your sender IP. This can have an impact on other users of your system too since your transactional emails might be blocked by their email system.

Verify new emails during signup using an email validation service using an API or plugin. Read more about how to use CampaignKit's API to integrate email validation into your existing system.

You send informational emails like product updates to your user base. Companies are likely using catch-all email addresses with low engagement. Some of the accounts might be created with disposable email addresses which could cause high bounces. To protect your sender reputation, qualify your target email list by removing such email addresses before hitting send.

Another use case is verifying your curated list for cold outreach. Before starting to contact your curated list, make sure to verify the email addresses. Again it's all about protecting your sender reputation and cold outreach is a good candidate to cause damage to it. People are more likely to mark you as spam. One piece of advice: Never buy an email list on the internet.  

How does email verification work?

Email verifier apply a couple of tests to an email address without sending an actual email:

  1. Domain validation - does the domain exist.
  2. Mail server validation - does the domain have an email server that accepts emails
  3. Mailbox validation - does the email server knows the mailbox.
  4. Disposable email detection - is the email address from a temporary email address provider
  5. Catch-All email detection - is the email address from a common catch-all account
  6. Spam trap detection - detect spam trap email addresses. This can never be 100% accurate though. Even if some providers claim it.

With email verification services you can instantly remove invalid and low-quality email addresses from your email lists.

Email Validation Result
Email Validation Result

The example above shows the results of CampaignKit's free single email verifier. In this case, the email verifier verifies that the email address is valid and emails will be delivered. It also detects the catch-all characteristic of the email address. The email address gets a lower scoring.


If you're looking for a way to clean your contact lists to protect your sender reputation, Email Verification Tools help you to remove invalid and low-quality email addresses from your lists.

But keep in mind to always follow best practices and never send emails that are considered spam to your audience. Email Verifier are an effective way to clean your data, but are not replacing common best practices.

Ready to use an Email Verification Service? Try it out and sign up for a free trial.  

Ready to dive in?Start your free trial today.