Last Updated Aug 04, 2023

Only the best: The Top Email Validation & Verification Tools

Elizabeth (Lizzie) Shipton

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If you are running a mailing list or are a wholly online business, you know the value of email marketing campaigns. Email marketing is the most effective form of online marketing, with the highest return on investment over ads, social media posts, and even paid spots in things like podcasts and YouTube videos.

Email validation is an important step in building a robust, healthy email list that will sell your products and services efficiently. Using email verification tools to keep invalid email addresses off your list is a necessary part of mailing list maintenance.

In this article, we'll look at different types of email verification services and dive into the ten best email verification service options available.

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Benefits of Email Verification Tools

Sender reputation is crucial when it comes to running effective email marketing campaigns. If your sender reputation is low, emails to potential new customers will go straight to spam. What causes your sender reputation to be low? Low engagement with your existing emails and high bounce rates.

Invalid email addresses (fake emails, unused emails, spam traps, and other defunct email addresses) are the biggest reasons for low engagement and high bounce rates. By removing inactive email addresses from your mailing list, you improve your sender reputation and ensure that your emails will make it into inboxes and get seen.

Types of Email Verification Tools

There are a couple of different ways to weed out invalid email addresses from your list. Most email verification tools offer at least one of these methods, and the best email verification services offer all three.

Real-Time Email Verification Tools

This is the most important thing you can do to ensure that invalid email addresses don't end up on your list. Validating email addresses in real-time means capturing the user input at the time they attempt to sign up to your list, and ensuring that the email address they give you is correct, well-formatted, and a real, active email address.

The process for doing this is simple - you can do some validation in your own code (for example, checking that there are no unexpected characters in the string or making sure that the user has input something that looks like an email address.)

For more advanced real-time email verification, use an email verification API. This type of email verification tool accepts an email address and runs several checks against it to look for invalid addresses, spam traps, inactive email addresses, do disposable email detection, and more.

Bulk Email Verification Tools

If you already have a list of addresses and you suspect there may be some invalid email addresses or inactive addresses on the list, you can use a bulk email list verification process to clean those addresses from the list.

To do bulk email list verification, you typically upload a CSV file containing a list of the addresses. The bulk email verification service will check each email in the list and let you know whether it is valid or not.

Email List Cleaning

Even if you do real-time validation, you will still need to do regular email list cleaning to ensure that your list stays healthy. You should use a bulk email list verification service at least once every 6 months to find and remove invalid email addresses from your list.

Top 10 Email Verification Services

Let's take a look at the top 10 email verification tools available to help you maintain an active, engaged, healthy email list.


AbstractAPI's Free Email Validation and Verification API exposes a simple REST endpoint that can be used for real-time email list verifications and offers a bulk uploader for validating a list of emails.

The service validates emails against several criteria: formatting, disposable emails, role-based emails, MX records, SMTP validation, and spam trap detection. It provides a quality score for the deliverability of the email.

AbstractAPI is free to get started with, and plans start at $9 for a monthly subscription.


  • The cheapest option on the list
  • Quick and easy to get started
  • Offers bulk and real-time validation


  • The free tier offers only 100 requests
  • No customer support at the free level

Price: $9 for 5000 requests/month, $49 for 50,000/month, $99 for 100,000/month


ZeroBounce specializes in email list cleaning through a bulk email verifier. They also have a REST API that is accessible through network requests and secured with an API key.

The free trial period is one month, and you get up to 100 requests during that time. They offer pay-as-you-go and monthly subscriptions. Pay-as-you-go starts at $0.008 per email for 2,000 email addresses. If you purchase a monthly subscription, the cost drops to $0.0075 per email.


  • A well-established email verification and validation company
  • Bulk email verification and real-time validation
  • Excellent support


  • Pricier than some other options
  • Minimum purchase of 2000 credits

Price: $16/2000 addresses (pay-as-you-go) or $15/2000 addresses (monthly), $390/100,000 (PAYG) or $350/100,000 (monthly), $1910/1,000,000 (PAYG) or $2050/1,000,000 (monthly)


People understandably get confused between ZeroBounce and NeverBounce. NeverBounce is slightly cheaper than ZeroBounce and less well-known. NeverBounce does not offer a free trial - you can just test the service on their website by uploading one email into their demo.

NeverBounce's prices are very reasonable. They offer a monthly subscription or pay-as-you-go pricing. Customer support is available but has been reported to be less consistent than ZeroBounce support.


  • Cheaper than ZeroBounce
  • Bulk email verification and real-time validation


  • No free trial
  • Customer support may be less than stellar



BriteVerify serves some of the biggest names in online business. They have been around for a long time and process over 1.5 million emails a day. Despite this, they are competitively priced. They offer a complete suite of email verification tools including bulk email verification and real-time validation.


  • Over ten years of experience
  • Integrates with existing platforms
  • Very reasonably priced


  • No free trial
  • Monthly subscription pricing is not readily available

Price: $40/5000 verifications, $325/50,000 verifications, $2250/500,000 verifications. Call for subscription pricing.


MailTester offers a bulk and real-time verification process for email addresses, as well as an inbox checker to help you track and improve the metrics that are most affecting your deliverability.

The email verification service has several facets: duplicate email removal, spam trap detection, risk validator, syntax verifier, complainer verifier, anti-grey listing, MTA validations, and more.


  • Combines both verification and deliverability tools
  • Support readily available via phone
  • Cheaper than ZeroBounce or NeverBounce


  • Less well-known so possibly less reputable

Price: $19/5000 emails up to $2039/5,000,000 emails (PAYG), $39/month up to $299/month for a full suite of tools including inbox monitoring and email campaigns


XVerify is the best email verification service for affiliate management companies. They provide bulk email verification, as well as a real-time email verification API. They also offer phone validation and physical address validation.

XVerify offers pricing that is a little more costly than other services on this list, and on their website, it is not clear if the prices listed are for a monthly subscription or pay-as-you-go.


  • Real-time email verification tools and bulk uploader
  • Mobile app


  • Pricey
  • The pricing structure is not clear on their website

Price: $5/500 emails, $10/1000, $750/250,000, $2500/2.5 million


The EmailChecker API is the only completely free option on this list, which may make it a good option for freelancers or developers looking to validate a few addresses, or for small businesses who are just getting started with email marketing.

EmailChecker offers a simple input on their website that accepts a single address at a time for validation. There is no real-time verification API or bulk upload option.


  • Completely free
  • Easy to use


  • Will not work at scale

Price: free account


The QuickEmailVerification API is trusted by some of the biggest names in industry, and has over 100,000 satisfied customers. They offer bulk email list verification, an email verification API and a suite of free tools.

Their free trial is the most generous on the list, offering 100 verifications per day for life. They offer pay-as-you-go pricing and monthly subscriptions.


  • Generous free trial
  • A simple website makes it easy to get started


  • On the higher side, price-wise

Price: $4/500 emails (PAYG) up to $3500/5 million, $25/month for 500 emails per day, up to $900/month for 50,000 emails per day.


Over 150,000 companies use Kickbox for their email verification tools, which include a bulk email list verification option, a real-time email validation service, blocklist monitoring, inbox placement, DMARC monitoring, and deliverability consulting.

Kickbox also offers some free tools, such as the email spam tester and disposable email detection API. That will automatically prevent invalid email addresses entering your CRM system.


  • A comprehensive suite of solutions that go beyond email verification tools
  • Trusted by many
  • Lots of easily accessible support channels (Slack, chat, email)


  • Pricey
  • Additional tools are costly

Price: $5/500 emails up to $4000/1 million emails. $250/month for additional deliverability tools, up to $500/month for an advanced suite of tools.


SendInBlue is now Brevo, and its services include a full selection of email marketing solutions including email verification tools, a marketing platform, a transactional email API, and more.

Brevo offers Brevo Academy to help people learn how to use their email verification services, marketing platform, and other tools. They also offer a generous free tier that allows up to 300 email verifications per day for life.


  • Full spectrum of tools is available to help with every aspect of email marketing
  • Competitively priced, with good support


  • May be overkill for people just looking for email verification services

Price: $25 per month for 20,000+ emails and basic tools. $65/month for 20,000 emails plus advanced tools and support.

Comparing Email Verification Services

Real-time Validation Bulk Validation Free Trial Price for 5000 emails Price for 100,000 emails
AbstractAPI X X X $9/month $99/month
ZeroBounce X X X $30 $390
NeverBounce X X $49/month $249/month
BriteVerify X X X $40 $350
MailTester X X X $19 $199
XVerify X X X $40 $400
EmailChecker X FREE FREE
QuickEmailVerification X X X $35 $320
Kickbox X X X $40 $800
SendInBlue X X X $0 (300 emails per day) $25/month or $65/month with advanced tools

Best Practices for Email Validation

When it comes to email list cleaning service solutions, there are a few things you can do to make the most of your investment. It isn't enough to simply bulk clean your list once and then be done with it, or rely on real-time validation to handle all your needs.

Regular List Cleaning

Use an email verification service at least once every six months to find and remove invalid addresses from your list. Even if you are using real-time validation to capture email addresses at sign-up, there will inevitably be some that slip through the cracks.

Track the email addresses on your list that are the least engaged and purge them diligently.

Double Opt-In

You should always require users to double opt in to your list. This means that once they have signed up, you send them a verification email that they must open and click a link to confirm their address before they are added to the list.

This might mean that a few people drop off during sign-up. But it is worth losing those few people to prevent spam traps and other bad actors from ending up on your list.

Real-Time Verification

This is your best defense against invalid addresses and should be your frontline email verification and validation strategy. Capture all email addresses and attempt to verify them before they are added to your list. This will make your overall list stronger and more engaged.

Integrating Email Validation Services into Your Workflow

Let's take a look at how to integrate an email verification service into your application. We'll use AbstractAPI as our example in this walk-through, as their service is very easy to get started with.

Get Started With the API

Sign up for a free account and get an API key. The key authenticates you and allows you to make requests to the API.

Click "Get Started" on the API homepage

You'll sign up with an email address and create a password. Next, you'll land on the dashboard, where you'll see your API key, and links to documentation, pricing, etc.

Send an Email Validation Request to the API

Let's look at the Javascript implementation for this tutorial. Copy the Javascript snippet provided in the testing sandbox.

This is a simple AJAX request that sends a GET request to the API with an email address for validation included as a query string argument. You will also need to paste your API key as a query string parameter.

The response from the API will look something like this:

  "email": "",
  "autocorrect": "",
  "deliverability": "DELIVERABLE",
  "quality_score": "0.80",
  "is_valid_format": {
    "value": true,
    "text": "TRUE"
  "is_free_email": {
    "value": false,
    "text": "FALSE"
  "is_disposable_email": {
    "value": false,
    "text": "FALSE"
  "is_role_email": {
    "value": false,
    "text": "FALSE"
  "is_catchall_email": {
    "value": true,
    "text": "TRUE"
  "is_mx_found": {
    "value": true,
    "text": "TRUE"
  "is_smtp_valid": {
    "value": true,
    "text": "TRUE"

You can pull values off this JSON object and use them in your code to determine the validity of the email.

Bulk Email Verification Service

Let's also quickly check out the bulk email verification tool.

Provide Your Email List as a CSV

Most email services provide an easy way to download your mailing list as a CSV file. This is what you will upload to the API to validate email addresses from the list.

Upload the CSV to the Bulk Uploader

Log in to the API and click "Bulk Upload (CSV.)" This opens a dialogue where you can upload your CSV file. The uploader will check all the email addresses on the list for the following things:

  • formatting and spelling
  • disposable addresses
  • MX records
  • SMTP records
  • role emails
  • catchall emails
  • free emails
  • deliverability

get the results

The results of using the bulk email verification tool will be emailed to you as a separate CSV. Click "Download CSV" in the email to view the results.

Evaluating the Effectiveness of Email Validation Services

Once you've used an email verification tool to validate email addresses, you'll want to monitor your results to make sure that the changes are having an effect. These are the things to look for when evaluating the success of your email verification tool.

Reduction in bounce rates

You should see a reduction in bounce rates. Email bounces occur when an email cannot be delivered to the intended recipient. There are many reasons for bounced emails, but the number one cause is attempting to deliver emails to invalid domains or addresses. Once you remove the invalid addresses from your list, your bounce rates should improve.

Improved Email Deliverability

A secondary effect of your email verification tools should be improved email deliverability. Fewer bounces mean your deliverability score will go up. Removing invalid addresses from your list will also increase the percentage of engaged users on your mailing list, which will also improve your deliverability.

Enhanced Sender Reputation

All of these benefits add up to an improved sender reputation, which will ensure that any new emails you send will get delivered to their intended inboxes and will not end up in people's spam folders.

Potential Drawbacks of Email Validation Services

There are a few drawbacks to using email verification tools, however, we believe that these drawbacks are minimal compared to the benefits you will reap from implementing them. Let's quickly take a look at some things to watch out for when using an email verification tool.


This is the number one reason people and businesses shy away from using an email verification tool. It can certainly become costly to verify email addresses if your list is very large or if you have a lot of incoming traffic. Again, however, we believe that the cost of having invalid domains on your list is much greater than the cost to verify email addresses.

False Positives

No email verification tool is perfect. There will always be some email addresses that slip through the cracks, or that appear to be valid when they are in fact not. This is just something that can't be avoided with email verification and validation.

If you find that your email verification tool is failing to catch a lot of invalid addresses, you might consider switching to a different solution.

Privacy Concerns

Always read the terms and conditions of any email verification tool you choose to ensure that they are compliant with all relevant data security policies and regulations. In particular, you need to be aware of GDPR concerns and CCPA if your customers reside in the EU or in California.


A healthy, engaged mailing list is the cornerstone of all online marketing efforts. Email marketing campaigns have the highest ROI over all other online marketing platforms. It's important to have a list full of real, active email addresses.

Email verification is an important step in building your strong, robust mailing list. You should be verifying all email addresses in real time before they sign up for your list, and you should be periodically cleaning your database to remove invalid and inactive addresses.

Utilizing an email verification tool is the easiest way to maintain a healthy, active email list.


What makes AbstractAPI's Email Validation API unique from other email validation services?

AbstractAPI's Free Email Verification API is the only API dedicated wholly to verifying and validating emails. We do not offer any email marketing services or platform integrations. This enables us to focus on providing an extremely accurate verification process for your mailing list.

How can I integrate AbstractAPI's Email Validation API into my existing applications or systems?

It's easy to get started with AbstractAPI's email verification tools - simply follow along with the documentation, or check out one of our API guides for help with specific languages and frameworks like Javascript, React, Python, Django, and more.

What programming languages does AbstractAPI's Email Validation API support?

AbstractAPI's Email Validation API is language-agnostic, meaning it can be integrated with applications written in any language. It exposes a simple REST endpoint, accessible via HTTP request.

On the API dashboard, you will find code snippets for Python, Ruby, Javascript, Node, Java, PHP, and Go. These are not the only supported languages - they are provided as examples and quick-start options.

Is there a free tier or trial available for AbstractAPI's Email Validation API?

Yes - you can use the AbstractAPI Free Email Verification API free for life. You get 100 requests per month. This translates to 100 email addresses verified by either the real-time API or the bulk email verification API.

Can AbstractAPI's Email Validation API be used for both real-time validation and bulk validation?

Yes. There is a REST endpoint that accepts network requests in real time for validating email addresses as users sign up for your service. There is also a bulk upload interface where you can provide a CSV file containing a list of addresses for verification.

What are the pricing plans for AbstractAPI's Email Validation API?

The API is free to use for up to 100 email addresses per month. Monthly subscriptions start at $9/month for 5000 emails, $49/month for 50,000 emails plus domain whitelisting and email/chat support. Upper tiers offer $99/month for 100,000 emails at 25 requests per second with dedicated support and multiple API keys, and the enterprise solution is $499/month for 750,000 emails, at 100 requests per second.

How accurate is the email validation provided by AbstractAPI's Email Validation API?

The AbstractAPI Email Validation service is trusted by companies like Accenture, Nokia, Stanford, and Shopify. They are backed by a powerful API and protected by bank-level security.

Does AbstractAPI's Email Validation API offer any additional features or functionalities?

AbstractAPI focuses on email validation and verification to ensure that they provide the best possible accuracy and service for this solution. They do not offer marketing tools, analytics, or help to create email campaigns.

5/5 stars (14 votes)

Elizabeth (Lizzie) Shipton
Lizzie Shipton is an adept Full Stack Developer, skilled in JavaScript, React, Node.js, and GraphQL, with a talent for creating scalable, seamless web applications. Her expertise spans both frontend and backend development, ensuring innovative and efficient solutions.
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