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What is an email verification API?

An email verification API (also known as an email address validation API) allows developers to build simple programs that automatically check whether an email is invalid, disposable or mistyped,  enabling better deliverability. 

An API is useful for organisations who want to integrate email verification software into their business applications.


What can I use the MORE email verification API for?

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On online forms to ensure the email contact information captured is legitimate

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To automatically clean your marketing database, freeing up time for you to focus on the more strategic elements of your campaigns

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To clean your CRM data automatically, ridding your system of any bad apples within your email lists

About the MORE email verification API

Our API solution, MORE, provides a fast, simple and secure way to validate email addresses in real time.

MORE can be used on sign-up forms, marketing platforms and CRMs when you need to verify an email address quickly and accurately. 

MORE performs a comprehensive check on every email address entered into the system, helping you make informed and automated decisions about the quality and trustworthiness of your email address data. 


MORE Product Plans

Edition 1

Best for speed

  • Verify up to 2.5 million emails per month
  • Monthly, quarterly or annual subscription
  • From $9.88 per month

Edition 2

Best for features

  • Verify up to 2.5 million emails per month
  • Monthly, quarterly or annual subscription
  • From $9.88 per month


Best for scale

  • Agreed contract duration and payment terms
  • Edition 1 and 2 features available
  • Contact us for pricing

MORE pricing


Please note GBP and Euro prices are indicative - the actual amount billed will be in US dollars.

Ready to get started?

Sign up for a free trial now and validate your first 100 email addresses.


Why Choose the Email Hippo API?

99.99% uptime

99.99% uptime

All email address data is processed on secure cloud servers in the UK, with a guaranteed uptime of more than 99.99%. This ensures our services are available whenever you need them.


Thoughtful versioning

All endpoints are ‘versioned’ to allow the release of new functionality without the need for you to break or change if you need to integrate with legacy endpoints.

API integration

Simple integration

Integration is so quick and easy - see technical resources for code samples to find out just how simple it is.

Quick response

Quick response times

Every query response includes stopwatch data, which displays the time taken to execute the request. Typically, queries are answered in 0.5 seconds.

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Unrivalled performance

We have strategic data centres in the UK, global network delivery optimisation, cloud-based auto-scaling and aggressive catching, we deliver outstanding performance.

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Email Hippo is a trusted email verification services provider for global enterprise clients. We pride ourselves on the security of our systems and monitor, audit and improve them regularly to make sure your data is secure at all times.

MORE email verification API features

Included in all Product Plans

Disposable email address detection 

Disposable email address detection 

We monitor new email addresses 24/7 to ensure you can block disposable email addresses that are commonly used for fake sign ups and fraudulent activity.

Role checks 

Role checks 

Role-based email addresses tend to have lower open rates than named email addresses. This feature allows you to spot email addresses that are for role-based inboxes and decide what to do with them.

Freemail detection 

Freemail detection 

This feature is especially valuable for email marketing efforts, as it allows you to identify whether email addresses are used for private or business emails.

Syntax checker

Syntax checker 

Our syntax checker identifies errors and typos in real-time, so you can create alert responses to prevent invalid email addresses from appearing on your lists.

‘Catch all’ mail server detection 

‘Catch all’ mail server detection 

Emails sent to ‘catch all’ mail servers tend to have low open rates and are more likely to allow redundant email addresses. Our MORE service allows you to learn which mail servers are set to accept all emails, increasing the value of your data in the long run.

Mail server location 

Mail server location 

This feature allows you to find out where in the world mail servers are really located. This is ideal for sorting through sales leads and filtering out fraudulent accounts.

Comprehensive dashboard 

Comprehensive dashboard 

Our dashboard provides easy-to-understand summaries and allows you to download details, as well as understand your data from every angle. Our user-defined layouts and flexible reporting tools make a simple process of analysing your data.

Clear results 

Clear results 

With MORE, you can create messaging and workflows to suit every situation, from stopping typis on a CRM to filtering gibberish from your sign up forms. It enables you to act on results from multiple data points.

Spam Trap Assessment Score 

Spam Trap Assessment Score 

Our trustworthy Spam Trap Assessment Score means you can avoid mailboxes that trap you on a ransom blacklist. Each result is scored, meaning you can predetermine the outcomes.

Included in Edition 2 only

The Trust Score

The Trust Score

Our Trust Score is a numerical result from 0-10 and is compiled from all the checks carried out on an email address. This score gives you an indication of the automation actions and decisions you can make for every checked email address.


Safe to send score 

Every checked email address receives a numerical score, which lets you know when you can safely and successfully send to that address.

Blocklist detection

Blocklist detection 

Our service allows you to disallow email addresses that have previously been blocklisted for sending spam, protecting your sender reputation. MORE also flags domains that charge gatekeeper fees to reach inboxes and collect sender details.

Mail system detection 

Mail system detection 

Mail system detection allows you to segment data better by providing details about the mail system provider. This insight means you can improve your delivery rates and tailor your communications for better marketing results.

Greylist detection 

Greylist detection 

Greylisting asks users to try checking email addresses later, so they can work out if requests are fake or genuine. MORE flags greylist servers, allowing you to choose whether you need to double-check email addresses.

MX record checking

MX record checking 

Mail exchange records (MX records) are settings within the DNS that redirect email to a predetermined mail server that accepts emails on behalf of users or a domain. Without MX records, your emails are undeliverable. MORE identifies each MX record and tells you if you are missing any.

Dark web link checks 

Dark web link checks 

This feature highlights domains that are connected to dark web users, ensuring you only have genuine contacts in your system.

Spam email address detection 

Spam email address detection 

MORE helps to keep your email list safe by detecting email addresses that contain random strings of characters, which often point to fraudulent or spammy emails.

Want to make the most of these features?

Get a free trial of MORE today.

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Getting started: How to use Email Hippo’s API

Our API is simple to use, and we have a free trial available so you can see for yourself. 

With MORE, you can call the email verification API within seconds and our comprehensive documentation offers a wealth of advice on our results and scoring processes.

Technical resources

How does the MORE API work?

The process of verifying an email address with an API is straightforward. Anyone can ping an email server to check whether an inbox exists or not. Where it gets more complicated is when we need to deal with mail services that are configured to work against email verification systems, or any similar Simple Mail Transfer Protocol (SMTP) activity, as a way to defend against spam and DDoS attacks.

Our strength in dealing with this aspect of email address verification comes from years of experience in validating email addresses, combined with our complete ownership of our SMTP verification software stack and cloud-based infrastructure.

Therefore, MORE tackles the most difficult aspects of email verification with ease and provides outstanding coverage on the more dynamic and technically challenging email domains.

How does the MORE API work


Don't have the technical resources to build your own solution using our API? Don't worry - you can still unlock the full power of email verification using one of our off-the-shelf integrations for MORE.

Thanks to our partnerships with Auth0 and Zapier, we've  made it easy to connect Email Hippo to your CRM, marketing automation platform, sign-up forms or ecommerce store.

Popular Email Hippo integrations include:



Automatically check the validity of every email you capture and stop bad actors at the gate of your Formstack forms. Connect with Zapier, API.



Check every contact email address to improve lead quality and reduce bounce rates. Connect with API, code snippet, Zapier.


Microsoft Dynamics

Provide better data for your marketing, sales and customer service teams by verifying email addresses at the point of capture. Connect with API, Zapier.



Keep your CRM free from bad data and junk emails by automatically checking every new lead’s email address. Connect with API, Zapier.



Connect to Email Hippo and check email addresses at the point of form submission, allowing you to block spam and junk from your Unbounce landing pages. Connect with API, Zapier.



Stop passing spam and junk mail into your business systems by adding email verification to your WordPress forms. Connect with API, Zapier.


Auth0 is a leading identity as a service (IDaaS) solution, allowing organisations across the globe to ensure their users are genuine.

You can add an extra layer of security to your sign-up forms by integrating Auth0 with Email Hippo to check users’ email addresses for signs of fraud.

This integration can be set up in minutes, with no need for coding knowledge.

Find out more


Set up smart automated workflows without a developer and connect Email Hippo to any of 3,000+ apps supported by Zapier.

Zapier is a user-friendly and simple integration platform as a service (IPaaS) solution that allows non-developers to move data easily between web apps.

Connecting Email Hippo to Zapier means you can verify email addresses taken from any other supported data source, whether that’s a CRM, form solution or email marketing platform.

Find out more

Looking for help with integrations?

If you’d like more information about our integrations, or would like to discuss an integration solution not covered here, get in touch with us today.

Alternatively, you can check out our integrations page for more details. 

What our API customers say
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It was just obvious that the accuracy was far better than anything else we'd experienced and that Email Hippo was a company we could do business with.

James Viney
Programme Manager
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We need our emails to be credible and influential. That’s why we’re happy with Email Hippo.

Florian Bolka
Head of Department - Digital Mobilisation
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How can I get an API key?

You can get an API key by signing up for a free trial

Can I trust Email Hippo with my data?

We pride ourselves on compliance and security, so you can certainly trust us to take care of your data. Read our compliance pages for detailed information and up to date information on our policies.

Is it possible to get blocklisted using your API?

The Email Hippo infrastructure does all the work, so you won’t be blocklisted. For this reason, nobody will know that you are querying an email address or domain. 

How do I call an API?

Once signed up, read the endpoint sections to learn more and view the code samples. For a JSON response, simply make a GET request to the endpoint to call the API. 

Will your system slow down during busy periods 

All our infrastructure is hosted in cloud-based platforms that have automatic scaling enabled. This kicks in during busy periods to offer more hardware resources to meet the demand, meaning that the system will not slow down.

Do you cache results? 

To deliver the speed and reliability our customers need, we cache verification results as follows:

  • Level 1 cache: CloudFlare based. Cache expiration is two hours. 
  • Level 2 cache: Microsoft Azure based. Cache expiration is up to 30 days.

Please note that we do not store any personally identifiable information in our cache infrastructure.

Can I get my usage in real time? 

Usage is available in the customer portal, or you can use the quota API for MORE Edition 2. 

What if your service says an address is valid, but I know it’s bad (or vice versa?) 

Email Hippo queries mail servers in real time, and mail servers respond with one of the following answers to a given email address:

  • Yes, the email address exists - SMTP code 2xx
  • No, the email address does not exist - SMTP code 5xx

We use these responses to determine if an email address is valid or not, and report it back to you. This process works in more than 99% of cases. However, in a small number of cases it is possible for a mail server to report one thing on email verification and do something different when trying to deliver an email to the verified address. If it was a temporary error, the result may be remembered by our server in the following few hours. 

An incorrect response could be due to an error with the target mail server. This happens only in very rare circumstances.

Try our email verification API for free

You can call the API in seconds, check any email address and analyse 74 critical data points quickly. Get a free trial of MORE today and see for yourself!