The Top 5 Email Validation & Verification Tools

Last Updated Dec 20, 2021
Emma Jagger

Engineer, maker, Google alumna, CMU grad

Table of Contents:

  • What are the best bulk email verification tools?
  • ZeroBounce.
  • Mailfloss
  • Email checker
  • Zoominfo
  • NeverBounce
  • Bouncer
  • DeBounce
  • Xverify
  • Send grid
  • What is an email validation tool?
  • How to check if an email address is valid?

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Your business has probably built up quite a list of contact email addresses over time. It doesn’t take long for such a list to become unmanageable or to build up many invalid email addresses. Also, in an era of phishing, you need to take control of your email lists again to remove dangerous or simply invalid email addresses. Also, failing to get hold of this issue can lead to preserve the sender reputation of your mail server and minimize spam complaints. So, here are the top 5 email validation tools and email verification tools to help ensure that you’re not sending to invalid email addresses.

What are the best bulk email verification tools?

Below, you’ll find a list of email validation tools to help you ensure that you’re not sending to invalid addresses and not sending invalid or undeliverable emails, highlighting whether it has a real-time email validation API.


ZeroBounce is a secure email validation service and bulk email list verification tool that can take your email list and clean it up with a claimed 98% accuracy. This is targeted at improving your marketing metrics.

Feature list:

  • High accuracy
  • Top level security
  • AI scoring and invalid emails checker
  • Email list enhancement
  • Deliverability tools
  • No charge for unknown results
  • Free duplication removal
  • Integrations
  • Round the clock support

Does it have an email verification API? Yes.

Free trial: The trial version provides 1,500 free credits for testing.

Pricing is per email:

  • up to 100 - FREE plan
  • from 2,000 - $0.008
  • from 5,000 -$0.0078
  • from 10,000 - $0.0065
  • from 100,000 - $0.0039
  • from 250,000 - $0.003
  • from 500,000 - $0.0022
  • from 1,000,000 - $0.001755
  • from 2,000,000 - $0.001525

Best for: Corporate or large organization environments where ZeroBounce’s adherence to GDPR, SOC 2, CCPA, and PCI is relevant.

What users say:


Mailfloss is an email validation service and bulk email verification app that will ensure that your emails only get sent to real people. It also supports Zapier to enable you to integrate with other web applications.

Feature list:

  • Up to 125,000 emails scanned/day
  • Whitelist/blacklist functionality
  • Unlimited ESP integrations
  • Zapier access
  • Auto-remove with category exclusions
  • Auto-update custom fields and tags

Does it have an email verification API? Yes and the API key can be generated from the Mailfloss dashboard,

Free trial: Free trial is available for supported services but no free plan.


  • Highest tier $0.001 overage per email
  • Middle tier $0.003 overage per email
  • Bottom tier $0.005 overage per email

Best for: Small or expert organizations where 24/7 support isn’t required.

What users say:

Email checker

Email checker’s email verification service stops invalid emails minimizing the risk of ‘hard bounces’ to ensure that your mail server’s reputation remains high.

Feature list:

  • Prevents emails to bad addresses from being sent
  • Bulk email verifier: up to 100,000 emails at once
  • Verifies syntax of address
  • Verifies domain
  • Verifies mailbox with ISP to remove invalid email addresses and mark any valid email address
  • API version supports up to 300,000 emails per month

Does it have an email verification API? Yes a RESTful API.

Free trial: Yes, but no free plan.


  • API 15k emails $99 per month
  • API 25k emails $125 per month
  • API 50k emails $250 per month
  • API 100k emails $500 per month
  • API 150k emails $600 per month
  • API 200k emails $750 per month\
  • API 250k emails $850 per month
  • API 300k emails $900 per month

Best for: Email marketing, lead generation.

What users say:


Zoominfo offers an email verification service and bulk email list verification to keep your email list clean. It also offers a range of other tools to deliver better intelligence, engagement and orchestration.

Feature list:

  • Compare emails to contact and company data
  • Enables prioritization of companies related to your business
  • Analyze emails to derive insights
  • Analyze relationship between email participants
  • Automation options
  • Lead enrichment

Does it have an email validation API? Yes with responses returned in JSON.

Free trial: Yes but no information on a free plan.

Pricing: Credit and monthly fee packages available, but details can only be sourced by contacting the vendor.

Best for: Lead generation with support for marketing operations.

What users say:


NeverBounce’s email verification service delivers email list cleansing and a bulk email verification service. It also offers a wide variety of integration options including HubSpot, Google and TypeForm.

Feature list:

  • Integrations with CRM, payment platforms and more
  • Email list cleaning
  • Real-time verification
  • Automated list cleansing
  • 99.9% delivery guaranteed, if more than 3% bounce the difference is refunded (see terms and conditions)
  • JavaScript widget

Does it have a real-time API? Yes in a variety of wrappers including PHP, Ruby and Python.

Free trial: Yes but no free plan.

Pricing is per email:

  • Up to 10,000 - $0.008
  • Up to 100,000 - $0.005
  • Up to 250,000 - $0.004
  • Up to 1,000,000 - $0.003

Best for: General email marketing for small to medium sized businesses.

What users say:

Honorable mentions of email verification services


This GDPR compliant email verification service and bulk email checker can verify a valid email address and be integrated with a range of other tools.

Pricing is per email:

  • 1,000 to 4,000 - $0.0050
  • 5,000 to 9,000 - $0.0040
  • 10,000 to 49,000 - $0.0030
  • 50,000 to 99,000 - $0.0025
  • 100,000 to 249,000 - $0.0020
  • 250,000 to 499,000 - $0.0015
  • 500,000 to 999,000 - $0.00125
  • 1,000,000 to 2,499,000 - $0.00100

Best for: General marketing campaign and ready for mail list management


DeBounce is one of the email verification tools which will verify email addresses and proactively remove ‘spammy’ addresses. This bulk email checker can help with all your bulk email list verification needs and verify email addresses in minutes.


  • 5,000 Verifications - $10
  • 10,000 Verifications - $15
  • 25,000 Verifications - $30
  • 50,000 Verifications - $50
  • 100k Verifications - $90
  • 200k Verifications - $140
  • 500k Verifications - $300
  • 1M Verifications - $500
  • 2M Verifications - $800
  • 5M Verifications - $1,500

Best for: Email marketers


This email verification tool and bulk email checker is focused on ending the ‘hard bounces’ you get and pairs this with intelligence options.

Pricing is per email:

  • 0 to 5K  - €0.0092
  • 5 to 10K - €0.0074
  • 10 to 25K - €0.0065
  • 25 to 50K - €0.0055
  • 50 to 100K - €0.0046
  • 100 to 250K - €0.0037
  • 250 to 500 - €0.0028
  • 500K to 1M - €0.0018
  • 1 to 2.5M - €0.0014
  • 2.5M+ - €0.0009

Best for: Marketing, e-commerce, sales, IT.

This email service uses machine learning to source company email addresses of prospective targets.

Pricing is monthly:

  • Free plan - 10 free credits / month
  • Basic - $49 for 300 credits / month
  • Standard - $99 for 1000 credits / month
  • Premium - $149 for 2000 credits / month
  • ULTRA - $399 for 10000 credits / month

Best for: Email campaigns, sales, recruitment, event management

Send grid

This email verification service pairs email list cleansing with real-time analytics and bulk email list verification.


  • Free plan - 100 emails/day forever.
  • Essentials - starts at $15.00 per month
  • Pro - starts at $90.00 per month

Best for: General and scalable to enterprise level needs.

What is an email validation tool?

An email verification tool is focused on ensuring that your email list is up to date. If it isn’t, then not only will you be getting low ROI on your marketing, your mail server is more likely to be identified as a spam server. This will cause real problems if you’re using services like MailChimp and could cause your server to get blocked entirely. Therefore, if you’re going to market effectively and responsibly by email, you’ll need to stay on top of this.

Bear in mind that neither email verification services nor IP geolocation APIs are a replacement for each other or for a solid email verification process. IP geolocation is great for helping ensure that users are pointed to web-based marketing content for their region, see the correct currency or minimizing cybersecurity threats.

Therefore, you need to consider whether and how you can combine the two as part of the suite of tools you use when validating email addresses to ensure that your business operates at maximum efficiency.

How to check if an email address is valid?

Here are three simple ways to check that an email address and make sure you're not sending invalid emails. Please note that these can vary depending upon the capabilities of any tool.

Remove illegal characters

If you’re able to remove illegal characters from email addresses, then that will minimize the risk of you sending to invalid email addresses. Even if you’ve sourced the email through legitimate means such as a form, if the user had a ‘fat finger’ moment or their phone decided to ‘help’ by autocorrecting, then you could have invalid addresses. Best to simply remove it and move on.


If your email verification tool can produce real-time analytics and a reliable verification process, and use these to update your email list, then that’s a vital tool. After all, if an email address bounces, then you don’t want to keep sending to it because that will only increase the likelihood of your mail server being identified as a hub for spam by your email service provider.

Ping a mailbox

This functionality, where available, can ping a mailbox to ensure that it’s capable of receiving email - a great email validation process. Even if an email address is valid, there are certain circumstances where a mailbox may be inaccessible despite not coming across invalid emails. Why not test it first using such email validation services?

Checking emails with validations tools

Failing to keep on top of keeping your email list clean is very risky. You might think you don’t have the time for that, but are you willing to risk your mail server being blocked by everyone you want to send to because it’s developed a bad reputation? You don’t have to do it all yourself. By using an email verification service, you can automate a lot of the work involved in the verification process so that you can focus on what you’re best at.

Checking emails with APIs

Using one of the best APIs to verify email addresses is the most efficient approach to avoid low quality addresses. It will enable integration with other tools that you may use such as CRM. Also, it’s way more efficient to have this functionality taking place automatically in real-time using online email list cleaning, rather than having one of your employees upload an email list. That isn’t what you hired them for, so let’s keep them productive.

Writing code to validate emails

While open-source libraries can be a good starting point, Python libraries may only be capable of returning limited information. To get responses that supply the data you need or to take advantage of API functionality or to ensure that your email verification tool is going to slot into your tech stack optimally, you may need to write your own code. It isn’t likely to be complex, but you may also like to explore what capability you have to do this internally and what level of support is available from your email verification API vendor.

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Start using Abstract's email validation API for free today
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