Every company which deals with email marketing should validate its contact list from time to time. For this purpose, you should use special email validation services. Here’s what email validators help you do: 

• Check the correctness of the email syntax: for example, you can find domain spelling errors, missing “@”, and delete such addresses.
• Find and replace duplicate emails.
• Detect spam traps and remove them. Spam traps look just like normal email addresses, but if you send an email to such an address, email services will consider email marketing campaigns from your domain as spam.
• Reveal contacts with a big number of spam complaints from them.
• Detect disposable email addresses, i.e., email aliases for users’ real addresses. Nobody reads any emails in such mailboxes. 
• Find role-based addresses, i.e. addresses associated with a certain company or position, not a person. Such addresses have high unsubscribe and complaint rates.
• Check mail eXchanger (MX) records in the addresses' domains. A domain without MX can't receive emails. 
• Check for an SMTP connection with the recipients' servers that shows if their accounts really exist.
• Detect contact activity/inactivity — whether the subscriber is currently using the given mailbox. 

This is an incomplete list, but nevertheless, it demonstrates well how many dangers there are in an unvalidated contact list. Especially if you’ve collected contacts offline — through questionnaires, surveys or flyers. Or if there was no Double Opt In enabled.
Using bad contact lists can lead to: 

• Useless waste of money,
• Falling into an email blacklist,
• Damaged sender reputation,
• Ban in your email service provider.

There are many services to validate email lists, but we have collected the best.

1. ZeroBounce

An online verifier that enables you to check your email lists in TXT and CSV formats.

Advantages: the service finds the missing information about email contacts, such as their first names, last names, gender and geolocation. ZeroBounce support is ready to assist you 24/7.

The pricing for 100k emails is $385. You can check up to 100 emails for free.

Features:

• Removing addresses with hard and soft bounces,
• Cleaning contact lists from spam traps and contacts with a high level of spam complaints,
• Finding additional information about contacts.

2. Email Verifier

Hunter’s email verifier is a simple and fast tool to check the validity of any professional email address. 

Advantages: Validations are made on multiple levels: format, domain information, the response of the mail servers, and comparison with our unique base of 100+ million professional email addresses.

Users on free plans can verify up to 50 emails/mo, paid plans start at $49 per 1000 verifications/mo.

Features:

• Ability to verify email addresses in bulk
• Available in the API
• One of the fastest and precise email verifiers
• Real-time check with Hunter’s unique email database
• The confidence score available for accept-all emails

3. DeBounce

DeBounce is a simple, fast, and accurate email validation and verification platform which providers a deliverability guarantee of 97.5%. It has validated more than one billion email addresses so far and earned a 5-stars rating with more than 420 unique reviews on TrustPilot.

Advantages: DeBounce offers more than 30 integrations with popular email service providers. There is no need to manually updates your email lists on your ESP. DeBounce updates your email lists directly from its dashboard with simple clicks.

Pricing: The pricing for 100K emails is $90. You can check up to 100 emails for free.

Verification includes:

• Remove Invalid Emails
• Disposable Email Checker
• Catch-All Domain Checker
• Syntax Eliminator
• Anti-greylisting Technology
• Spam-trap Removal
• Team Account

4. Voila Norbert

Voila Norbert offers a powerful yet affordable email verification tool that uses advanced algorithms to weed out unresponsive domains, removing duplicate entries and incorrect emails. It can clean your email list in just a few minutes. Large enterprise companies like Facebook, Airbnb, Intel, Oracle, and Twitter have all used the platform.

Advantage: You can use Voila Norbert's email verification tool anywhere without having to install any software. All you have to do is to go to their website, upload your list in a CSV format or copy and paste your straight to the tool, and the software will do the rest for you.

Pricing: Unlike many email validation services, Voila Norbert uses a pay-as-you-go model. It charges only $.003 per address up to 500K addresses and $.001 per email beyond that limit. To use bulk validation, you need a minimum $2 spend, or around 667 email addresses.

Verification includes:

• Duplicates,
• Syntax validation,
• Domain verification,
• Inactive, invalid and parked domains
• Inactive email addresses,
• Disposable, catch-all and role-based email addresses,
• SMTP verification

5. Clearout

Clearout’s email verifier allows you to validate emails in seconds to ensure deliverability and fraud detection for your email campaigns.

Advantages: 20+ email validation checks provide precise data verification, giving you complete confidence in your email campaigns. This enables you to complete company data enrichment in the future with maximum precision and confidence. Over 100+ integrations with ALL online forms, landing pages, and other highly-demanded tools and platforms such as HubSpot, Mailchimp, Zapier, and WordPress. Rated 4.9/5 on G2 Crowd for accurate validation. Trusted by 30000+ multi-sized businesses.

As for pricing, one credit is charged per billable email with a 60-day money-back guarantee, no matter the reason. Try it out for free (no credit card required.)

Features:

• Speedy verification process.
• Ability to carry out high-volume emails in bulk with a download/export feature.
• Instant verification for millions of email addresses through REST API.
• Accessibility to Clearout’s Javascript Widget and WordPress Plugin for blocking spam leads as they appear.

6. QuickEmailVerification

QuickEmailVerification offers verification of email lists in real time. This includes the ability to connect the validation tool to the registration form by API.

Advantages: real-time email validation.

The pricing for 100k emails is $320. You can check up to 100 emails for free.

Features:

• Checking the correctness of the address syntax,
• Detecting contacts with a large number of spam complaints,
• Revealing role-based addresses,
• Finding disposable email addresses,
• Detecting suspicious domains.

7. Mailbox Validator

A validator with the ability to check MX records.

Advantage: the original numeric contact rating system. Typically validators segment contact list into 3 main groups:

• Active, 
• Conditionally valid, 
• Invalid. 

MailValidator works in a similar way, but with a more detailed gradation. All contacts have the rating:

• over 0.70 — active, 
• between 0.70 and 0.40 — conditionally valid, 
• under 0.40 — invalid. 

This way, you can determine the boundaries of the contact quality on your own.

The pricing for 100k emails is $200. You can check up to 100 emails for free.

Verification includes:

• Syntax,
• MX-record,
• Spam traps,
• Disposable email addresses.

8. BriteVerify

BriteVerify aims to ultimately simplify the validation process for your contact list. For example, you can drag and drop the list of contacts right into the check window, or import it directly from your ESP.

Advantages: the ability to enable validation for subscription forms via the API. The service offers support via the phone in the USA and Great Britain.

The pricing for 100k emails is $1000. A free trial is available.

Verification includes:

• Syntax,
• Role-based addresses,
• Сontacts with a large number of complaints,
• Disposable email addresses,
• Suspicious domains.

9. Snov.io

Snov.io Email Verifier is a comprehensive and efficient email validation and verification platform  with a user-friendly interface and advanced algorithms, which ensure fast and accurate email verification results. Snov.io Email Verifier has successfully validated over one billion email addresses, establishing itself as a trusted solution in the industry and having garnered G2 acclaim.

Advantages: Snov.io offers both single and bulk email verification, instant email check for validity upon finding, integration with over 5, 000 tools, and API that can build directly into your platform for integrated email validation at registration or lead form sign-up. What is more, you can use Snov.io Email Verifier together with other Snov.io tools included in the plan such as free CRM, Email Finder, Email Drip Campaigns, Email Warm-up, and Email Tracker. 

Pricing: The pricing for 100K emails is $738. You can check up to 150 emails for free within a renewable Trial plan.

Verification includes:

• MX record check
• Syntax check
• Gibberish check
• Catch-All Domain Checker
• Domain existence check
• SMTP authentication
• Freemail check
• Team Account

10. Mailfloss

Mailfloss integrates with MailChimp, Campaign Monitor, HubSpot, Constant Contact and many other ESPs. In just a few clicks, the service will connect to your account validate your contact list on a daily basis.

Advantages: you don't need to export contacts from your ESP, upload them to the validator, and remove invalid emails manually, then upload the validated list into ESP again. The entire process is streamlined thanks to the integrations.

The pricing for 100k emails is $150.

Verification includes:

• Syntax,
• Role-based addresses,
• Сontacts with a large number of complaints,
• Disposable addresses,
• Suspicious domains,
• Daily validation schedule,
• Ability to customize all the functionality.

11. EmailMarker

EmailMarker is one of the oldest and most credible email validators. The service validates emails in real time via the API.

Advantages: 24/7 support by email, phone or chat.

The pricing for 100k emails is $161. You can check up to 100 emails for free.

Verification includes:

• Syntax,
• Duplicates,
• Spam traps and complaining contacts, 
• Non-existing and inactive domains,
• Addresses with bounces.

12. Xverify

Xverify is a multifunctional system for the validation of email addresses, physical addresses, and phone numbers.

Advantages: the ability to add validation to subscription forms using the API, 24/7 support.

The pricing for 100k emails is $400. You can check up to 100 emails for free.

Verification includes:

• Syntax,
• Duplicates,
• Spam traps and complaining contacts,
• Disposable addresses.

13. Hubuco

Hubuco is a fast and reliable British system for email validation.

Advantage: 7 times faster than the competitors’ validation speed.

The pricing for 100k emails is $175, with a free trial.

Verification includes:

• Syntax,
• Duplicates,
• Disposable and role-based addresses,
• MX-records,
• SMTP verification.

14. Email Сhecker

Email Checker provides a real-time email verification API.

Advantages: a user-friendly dashboard with drag and drop functionality.

The pricing for 100k emails is $299.

Verification includes:

• Syntax,
• MX records,
• Online protection from dangerous and invalid addresses via the API.

15. Our platform

Our omnichannel CDP is, above all, a marketing automation software, not a validator. But there's also a number of free email validation features, such as:

• Verification of email syntax;
• Removing duplicate email addresses;
• Checking for blacklisted addresses.