10 best email verification tools to boost deliverability and keep your list clean

This article will look at 10 of the best email verification tools available so you can choose one that meets your needs. We’ve listed the key features to look for, broken down the different statuses shown by the tools, and highlighted what makes each one special.

What to look for in an email list verification tool?

The best email list verification tools make it easy to rapidly identify and remove low-quality email addresses from your list. They do this by scanning all your email addresses and testing them for different issues. 

Here are some of the main features to look out for: 

Bulk email verification

This is the basic functionality that all email verification tools need. All the tools on our list allow you to upload a spreadsheet with your emails to bulk-check your list and then export it as a list of emails. 

ESP integrations

As well as bulk uploads via spreadsheets, most email verification tools integrate directly with your email service provider (ESP) or CRM to streamline the import and export process. Look for a tool that works with the provider you use.

Reports

All the email validation tools will generate a report that shows the percentage of good, bad and risky emails on your list. 

Some also provide further details about why the emails have been classified in a particular way. This is especially useful for email addresses in the risky factor, as it allows you to make a more informed decision about whether or not to send to them. 

Real-time email verification

Most of the tools on this list have an API you can use to add email verification to forms to check email addresses as people enter them. 

This reduces the chances of bad emails entering your list by identifying and blocking:

1. Invalid email addresses with typos or syntax errors

2. Fake or disposable email addresses

3. Bots or spam email addresses 

With real-time verification in place, you’ll build a higher-quality list that you can more easily maintain between scheduled bulk cleanings. You’ll also ensure that people who want to join your list don’t miss out on your messages because they accidentally used an email address with a typo. 

Email deliverability tools

Email verification is just one part of an overall email deliverability strategy. The best email verification services also come with tools you can use to ensure your emails hit the inbox, such as:

• Content analysis to identify problems that could impact deliverability like spam words, broken links, or poorly formatted HTML

• DMARC reporting to monitor sending activity on your IP and keep your domain secure

• Blocklist monitoring to be alerted if your domain is placed on a blocklist 

• Inbox placement testing to estimate where your emails will land in the mailboxes of major providers

These are all useful ways to protect your email deliverability, although they won’t impact the actual email verification process.  

GDPR-compliant

Security and privacy are extremely important factors to consider when you upload customer email addresses to a third-party platform. 

If you’re based in the EU or have customers in this region, choose a tool that is advertised as GDPR-compliant so you don’t break the rules when cleaning your list. 

Delivery guarantee

Most tools offer a delivery guarantee that emails sent to cleaned lists will result in a minimum percentage of successful deliveries, typically between 95% and 99%. 

One thing to note is that a higher guarantee won’t result in a higher number of delivered emails if the number of emails the tool approves is lower. 

In our testing, the tool with the highest guarantee (99%) only marked 64% of the 100 emails as deliverable. Most other tools, including MailerCheck, marked around 80% of emails as deliverable and had guarantees of 97% to 98%.

As 99% of 64 is 63.36 and 98% of 82 is 80, you’d get a much higher guaranteed number of deliveries with MailerCheck despite the 1% lower guarantee. 

What do email verification tools look for?

Email verification tools remove email addresses that will either result in bounced emails or those that are unlikely to belong to real subscribers who read and engage with your content. 

The exact naming conventions may differ slightly from tool to tool, but your report will include the following 3 categories:

• Send to: Email addresses that are safe to send to

• Do not send to: Email addresses that are almost certain to bounce 

• Risky: Email addresses that have a high probability of bouncing or being ignored. Exercise caution when sending to addresses in this category

There are several reasons why emails may end up in each category. Here are some of the most common.

Do not send

Mailbox not found

There is no inbox associated with the email address. This could be due to syntax errors, typos, out-of-use accounts, or someone (or a bot) using a fake email address to join your list. 

Mailbox blocked

The inbox provider has blocked the inbox from receiving incoming emails. Any emails sent to these inboxes will bounce. 

Disposable

Some inbox providers let users generate disposable email addresses they can use to protect their privacy. These typically accept emails for a short period before being discarded. 

Since you don’t know whether the address is still in use and most likely the subscriber won’t engage with your email, avoid sending to these accounts. 

Risky

Catch-all 

Businesses use catch-all (also known as accept-all) domains to receive all messages sent to any account with the domain name. 

Emails sent to email addresses belonging to catch-all domains will be delivered but engagement can be low as there’s no guarantee that they will reach an inbox belonging to a real person.

Mailbox full

Full inboxes are real but no longer accept incoming mail. Often, this is because nobody manages the account. There’s a chance that these inboxes will accept future emails if someone frees up space, but it’s unlikely.

Role-based 

Role-based emails belong to a team in an organization rather than an individual. These inboxes will accept mail but will often be ignored. [email protected] and [email protected] are examples of role-based email addresses. 

Unknown

These are email addresses that can’t be categorized by email verification tools. Since they aren’t guaranteed to be valid, you should send to them with caution. 

Verification status comparison table

Below is a table that shows the statuses contained in the reports of each email verification tool. 

Not showing up in the report doesn’t mean the tool won’t discover these emails. For example, syntax issues and typos will often fall under the Mailbox not found category. 

But not including the status in reports means you won’t know the exact reasons why statuses come back as they do. You won’t be able to make informed choices about whether to send to email addresses in these categories.

The 10 best email verification tools

MailerCheck

MailerCheck is a suite of email verification and deliverability testing tools with an extremely user-friendly interface. You can verify your list by uploading a spreadsheet, integrating with popular email service providers, or using the email verification API. You can also verify single email addresses. The verification process is fast and you can view results while the check is in progress. 

The standout feature is the report, which clearly highlights whether the email addresses are allowed, risky, or do not send, while also breaking the categories down to show the exact reasons for the statuses. This is especially useful as MailerCheck can identify more types of emails than many other tools.

In-depth reports also make exporting your list a breeze: simply check the categories you want to include and either export the addresses back to your connected tool or hit download to receive a file you can upload to your email marketing platform. Any duplicate email addresses are ignored and the tool doesn't charge double if your email list has the same email address on it twice.

Beyond email verification, MailerCheck has a whole suite of deliverability tools to ensure your email marketing campaigns reach the inbox.

These include:

• Inbox insights: Predicts whether your email will land in spam or reach the inbox of major inbox providers

• Email insights: Analyses your email content for signs of spam and offers suggestions for improvement

• Blocklist monitoring: Alerts you if your domain is placed on an email blocklist, helping you avoid the spam folder

• DMARC monitoring: Stay secure by monitoring emails sent from your domain

Combined with the email verification tools, these features make MailerCheck a powerful tool for optimizing your deliverability. 

MailerCheck also offers single sign-on (SSO) with MailerLite, so if you use MailerLite for your email marketing you’ll be able to use MailerCheck with the same account details.  

Key features

• Bulk and single email verification

• API access for real-time verification

• Integration with popular ESPs

• In-depth reports and export

• Email deliverability tools

• GDPR compliant

• 98% deliverability guarantee

• 200 free credits

Emailable

Emailable is an email verification and deliverability tool. Cleaning your list via spreadsheet or integration is super easy and results in a nicely presented report split into the categories deliverable, undeliverable, risky, unknown, and duplicate. 

The standout feature is that you can view individual email addresses to see how each one was categorized. You can then choose which emails to export to your ESP, giving you granular control over the export process. 

Key features

• Bulk and single email verification

• API access

• Integration with popular ESPs

• Reports

• Email deliverability tools

• GDPR compliant

• 99% deliverability guarantee

• Free plan with 250 credits

Bouncer

Bouncer is an email validation service with deliverability features. It stands out because you can estimate your list’s bounce rate before cleaning, which helps you decide whether or not to clean it. By not cleaning lists with a low estimated bounce rate, you’ll save credits and cut costs. Although in most cases it's beneficial to clean your list even if the bounce rate is relatively low.

When you run a check, the report groups your emails into deliverable, risky, undeliverable and unknown. However, the tool doesn’t provide more information about why it groups the emails on your list.

Key features

• Bulk and single email verification

• API access

• Integration with popular ESPs

• Reports

• Email deliverability tools

• GDPR compliant

• 100 free credits

Clearout

Clearout is an email list verification and sales prospecting tool. You can easily upload a file or connect to popular ESPs with built-in integration and then choose to optimize your list based on either accuracy or turnaround time. 

The tool clearly groups your emails and provides a more detailed breakdown in the verified results section. From here, you can click to download your results and choose which ones to download.

Key features

• Bulk and single email verification

• API access

• Integration with popular ESPs

• Reports

• Sales prospecting features

• GDPR compliant

• 97% deliverability guarantee

• 100 free credits

NeverBounce

NeverBounce is a dedicated email list verification tool. It has a useful list analysis feature that will estimate list health and tell you if the list would benefit from cleaning. This is free to use and can help you save credits by not analyzing lists that are in good health. 

The results page is clear and the tool groups the email addresses into valid, accept all, unknown, disposable and invalid. At this point, you can’t see any further information about why each email is on a specific list, although you can choose to download or not download different types of emails during the export process. 

Key features

• Bulk and single email verification

• API access

• Integration with popular ESPs

• Reports

• GDPR compliant

• 97% deliverability guarantee

• 5 free credits

ZeroBounce

ZeroBounce is an email list verification tool with deliverability features. Once you’ve created an account, verifying your list is easy: you’ll see a list of official integrations you can use to import subscribers or you can upload a CSV file with your list.

The tool will then generate an easy-to-read report that groups the email addresses and highlights the issue. A unique feature is that the tool will also guess the user’s name and gender from the email which can help you personalize bulk outreach emails. 

Key features

• Bulk and single email verification

• API access

• Integration with popular ESPs

• Deliverability features

• Reports

• GDPR compliant

• 99% deliverability guarantee

• 100 free credits

Kickbox

Kickbox is an email verification tool with a super simple UI. Bulk verification is easy and the tool generates a simple report that categorizes each email as deliverable, risky, undeliverable or unknown, and also further breaks it down into categories such as role-based emails, disposable and catch-all. 

Sendex score is the standout feature. This uses an algorithm to estimate the quality of an email address based on several factors to help you decide whether to send to that address. You can also see the average Sendex score of all email addresses in a particular list, which could be useful for quickly analyzing the quality of email addresses from different sources. 

Key features

• Bulk and single email verification

• API access

• Integration with popular ESPs

• Reports

• GDPR compliant

• 95% deliverability guarantee

• 100 free credits

Million Verifier

Million Verifier is an email list verification tool that focuses on the core features you need to verify email addresses. These include single and bulk email verification, API access, and reports. The email verifier tool also integrates with 17 top ESPs, meaning there’s a good chance that yours will be on the list. 

When you finish a report, the tool will break your results into Good, Risky, and Bad email addresses and you can then download your chosen segments. The standout feature is that you can set up an automation to check subscriber lists on connected email marketing platforms regularly. 

Key features

• Bulk and single email verification

• API access

• Integration with popular ESPs

• Reports

• GDPR compliant

• 95% deliverability guarantee

• 100 free credits

EmailListVerify

EmailListVerify is a simple tool with the core features you need to verify your list. The test itself is fast and shows whether your emails are valid, invalid, spam-traps, accept all, disposable, unknown or duplicates. 

When downloading, you can easily choose from pre-built categories like safe to send, or get granular and choose which categories to download from all the available options. 

Key features

• Bulk and single email verification

• API access

• Integration with popular ESPs

• Reports

• GDPR compliant

• 100 free credits

Hunter

Hunter is a sales outreach tool with email address authentication features. When verifying single emails, the tool will provide extra relevant information including images. You can also use the tool’s email finder to discover email addresses for people with just their name and company. 

The downside is that you must have a monthly subscription to Hunter’s sales outreach features to access the email verification tool. It also lacks some key verification features like ESP integration and real-time verification via API. 

Key features

• Bulk or single email verification

• Reports

• GDPR compliant

• Sales outreach features  

• 50 free credits

Now’s the time to choose

The easiest way to choose an email list verification tool is to sign up for a few different options and start by making use of the free credits or verifying a small segment of your list. 

This will give you a good feel for which tool you like. You can also send an email to the verified list and see how the bounce rate compares to your other segments. 

And if you’re looking for an accurate email list verification tool backed by 12 years of email experience and guaranteed 98% email deliverability rates, give MailerCheck a try!