Email Verification | #1 email verifier & validator | WhoisXML API

#1 Email Address Verification and Validation Services

Tired of bounced messages and invalid email addresses? Boost email marketing results and get rid of abusers with our complete email verification product line—API, web-based lookup tool, bulk processing capabilities, and disposable email domains database.

Get started

100 free API requests. No credit card required.

For every email, our email verification and validation products answer these questions and others:

  • Is the syntax correct?

    Valid email addresses should conform to established IETF standards. We check for this via a syntactic email validation engine.

  • Is the address custom?

    Email addresses used for business purposes are more likely to be branded and include a company's name.

  • Is the email address disposable?

    Chances are disposable email service providers do not supply valid email addresses. Mostly users with short-term needs use temporary email addresses.

  • Does the mail server exist?

    Valid email addresses should have a corresponding domain name with configured MX records. If not, these addresses might be inaccurate.

  • Does the mailbox exist?

    A valid email address should be able to receive messages. Our email verification products check for mailbox existence via email-sending emulation and SMTP connection checks.

  • Is it a catch-all email address?

    It’s unlikely for valid email addresses to be catch-all ones since these are not designed to reach a designated person.




Download product sheet

Choose the email verification product that works best for you:

Email Verification Lookup

A hosted email verification tool to instantly verify the quality and validity of an email address via a lookup query.

Email Verification Lookup | WhoisXML API
Email Verification API | WhoisXML API

Email Verification API

Email Verification API thoroughly evaluates email addresses in an instant via API calls. We provide developer libraries for most programming languages to make integration quicker with less code to write.

Bulk Email Verification

Our online bulk email checker is easy to use. Just upload your email list for validation and download the results in your chosen format—XML, JSON, or CSV.

Email Verification Bulk API/GUI | WhoisXML API
Disposable Email Domains Database | WhoisXML API

Disposable and Free Email Domains

Get an exhaustive list of all disposable & free email domains in use to get rid of unwanted email addresses from your contact lists and more.


Learn more about Disposable Email Domains
Learn more about Free Email Domains

Our email validation process is:

  • Complete

    We cover email verification from many angles to significantly improve the quality and validity of your email lists as well as flag suspicious email addresses.

  • Timely

    Our data never gets old. We scan the Web daily to provide comprehensive information on all email domains.

Practical usage

Boost Email Delivery

Verify or validate customer and potential client email addresses so they receive your messages.

Avoid Freemium Abuse

Keep out disposable and other unverifiable email addresses out of your contact list.

Prevent Email Bounces

Reduce email bounces to increase your sender score and ultimately improve your email marketing campaign quality. Too many bounced messages leads to a low sending score and may land you in spam blocklists.

Enhance Customer Service

Provide the best customer service by ensuring your payment card expiration notices, receipts, and marketing offers end up in your subscribers’ legitimate inboxes. Help users easily reset their passwords in case they forget them by making sure they input valid email addresses.

Email Verification Overview

Get 100 free requests. No credit card required.

Get started