50 Best Email APIs for Developers

Email is one of the best tools for businesses to communicate with consumers. It is simple and universal, used for a variety of communications including transactional emails, customer support, and more. But it is difficult to build a complete infrastructure for emails from scratch. Many service providers, such as transactional email services, provide various plug-and-play solutions, enabling businesses to make use of the existing infrastructure to build an email notification system. Developers can make use of this existing infrastructure with the help of APIs.

Email service providers have APIs that can be used to programmatically generate emails according to context written in code. Such services help to automate many processes related to sending and receiving emails. There are other complementary email tasks that developers can make use of APIs to accomplish. In this post, we’ve rounded up 50 of the best, most useful email API services for developers. These APIs are used for various functions and are not ranked or rated in any way.

1. Amazon SES API

The email service offering that is part of AWS cloud is Amazon SES. SES stands for ‘Simple Email Service.’ The service has a robust API infrastructure that developers can use. It has extensive documentation and a robust support environment. The Amazon SES API can be used to build a highly scalable email infrastructure for any business.

2. Gmail API

Gmail has billions of users and is the most used email service among consumers. The Google cloud service provides email services that can be used by businesses. The service is supported by API access. This gives developers a powerful set of tools for email delivery and other allied services. APIs can be used to successfully integrate email functionality with your business’s web infrastructure.

3. MailGun API

Many email services are built to be used by different types of users, but MailGun is a service designed with developers as the core focus. This makes the MailGun API much more versatile for developer use. This attention is also reflected in the other aspects of the service. Mailgun’s SLA ensures 99.99% uptime, ensuring high deliverability. MailGun also provides a fast and accurate email validation service with API access.

4. Outlook REST API

Outlook email service is from the stables of Microsoft Azure cloud services. It provides REST API services for developers. Microsoft Outlook 365 is one of the most commonly used email management applications among businesses. The REST API gives developers access to the millions of users who use Outlook 365. It can also be integrated with calendars, contacts, notifications, and a slew of other Microsoft services.

5. Postmark Email API

Postmark is a reliable service that can be used to set up transactional emails. The service also has a robust API ecosystem that can be used by developers. With extensive API documentation and useful migration guides, shifting to the service is easy and friction-free.

6. Twilio SendGrid Email API

SendGrid was a popular email service provider that was acquired by Twilio, the messaging API provider. The service is now named Twilio SendGrid and combines the best from both of the pre-merger entities. The service also has an API that can help to automate all of an organization’s email processes. There is documentation support for all the popular programming languages such as Curl, Node.js, Ruby, Python Java, etc. The interactive documentation makes developers’ lives easier.

7. MailChimp

MailChimp is one of the earlier service providers that offered easy and simple email solutions for businesses. The company also offers two different API services: one for marketing emails and the other for transactional emails. Developers can easily track data with the marketing email APIs, while the transactional email API offers developers extensive ability to create event-driven email infrastructure.

8. Elastic Email API

Elastic is a highly scalable and reliable email service that offers an HTTP API for developers. With an easy setup and integration process, it’s a popular service used by many organizations. The API also has strong security features with multiple API keys for different access levels that can be assigned to different users. The various tools that complement Elastic Email API can also be used to ensure high deliverability.

9. Mailjet API

This service from Pathwire places an emphasis on transactional emails. It gives developers access to the Mailjet SMTP platform and API. The API can be used to gain real-time reporting for all traffic. The API service has various code wrappers for different programming languages including PHP, Python, Ruby, Java, etc. Mailjet also offers plugins for easy integration with various software platforms like WordPress, Magneto, and Google Cloud.

10. Reacher API

Sending emails to unverified addresses could result in emails bouncing, which wastes computing resources and network bandwidth. It also affects the quality of the server from which the email was sent. To counter that, sending emails only to verified email addresses is the better way to manage email. Reacher is one of the most popular APIs that developers can access to verify email addresses. This helps to weed out bogus emails and clean up the contact list.

11. Hunter API

Hunter is a popular service that’s often used for sales purposes. The application has a gigantic, curated directory of executives in most organizations along with the email contact details of almost all of those executives. Hunter also offers an API service that can be used to automate many processes in the sales funnel.

12. SendInBlue

SendInBlue has a host of tools for digital marketing, including a strong API for sending emails. It can be used to schedule emails as well as to create event-driven emails. The solution is also available as a white-labeled subscription. Solutions built with the white-labeled product can be sold to other businesses. The extensive API documentation makes the work of developers easier.

13. Snov.io API

Snov.io is a platform that helps to generate more leads and, in turn, increase sales conversions for businesses. The company’s major product is its email finder and verifier. Businesses can utilize this service to find the verified email addresses and other contact details of prospective clients. The service is also available in the form of an API, which can be used to create code that can automate various sales processes.

14. Pepipost

Pepipost is the email section of the customer engagement platform Netcore. The service offers an API platform that is easy to integrate with the IT infrastructure of any business. The scalable platform comes with a host of artificial intelligence features that can be used for tracking, monitoring, and analytics.

15. NameAPI Disposable Email Address Detector

In a list of email addresses collected by a company, it’s likely that some respondents have provided disposable email addresses. The address will be valid and can be verified, but it can be disposed of at any time. Sending emails to such addresses will result in the email bouncing, and it diminishes the quality of the mail server. To avoid such instances, NameAPI offers an API that can be used to detect disposable emails. Using this service helps to clean up the address book and preserve the quality of the mail server.

16. Email Hippo API

Email Hippo offers services to verify email addresses and other data services. The service also has a robust API ecosystem for integrating email validation with the services of any business. The service checks 74 data points related to email addresses to give a unique Hippo Trust Score about the veracity of email addresses.

17. Marcom Robot

Marcom Robot is a sales-focused service that offers a host of products. One of the company’s most popular tools is the Company Name-to-Domain matching tool. Sending emails to the wrong server is waste of time and resources. This tool matches the company with the right domain to identify accurate email addresses. The service is available as an API for bulk matching and to be part of automated code.

18. SparkPost API

SparkPost makes intelligent tools to plan and optimize sending emails. The service also has a strong REST API platform that can be easily integrated with any app or website. The API can be used to automate templates, messages, sending emails, and reporting. The API can be used in programs of different languages such as Python, PHP, Java, and C#.

19. turboSMTP

This company is a professional SMTP service provider that also has an email API framework for developers. The API can be used to automate transactional emails and other scheduled emails. The easy-to-integrate API platform can be set up in just minutes. The API also makes it easy to track and monitor campaigns.

20. Email Verifier API

Verifying email addresses before adding them to the address book and sending emails is the prudent way to reduce the likelihood of bounced emails. Email Verifier API can be used to mass verify email addresses before sending transactional emails. The API is compatible with all the major programming languages and boasts a 98% accuracy rate.

21. Kickbox Email Validation

Kickbox is an email validation platform that can be used by both marketers and developers. Developers can make use of the email validation API to automate the process and integrate it with a business’s other digital tools. The API provides real-time data that can be used for tracking and monitoring. The service has libraries in various programming languages, making it friendlier for all developers.

22. Byteplant API

This is another email validation service available as an API. The service can be integrated with a website’s signup pages and applications to ensure that users are entering valid emails. This helps to avoid sending transactional emails to bogus emails. The API can be used to validate emails using code with many programming languages.

23. BriteVerify

This is a tool from the performance marketing company Validity. BriteVerify can be used to improve the quality of available data, which helps in increasing the ROI of sales processes. The scalable and fast email verification service is available as API to automate the email validation process.

24. mailboxlayer API

This service provides verification and validation of email addresses as an API platform. It has an easy-to-integrate URL structure delivered in JSON format. The security of the service is ensured by 256-bit HTTPS encryption. The advanced email verification and validation tools are available as a cheap subscription service.

25. MillionVerifier API

MillionVerifier is an email verification service that can verify large volumes of emails. This helps to maintain the reputation of the email server by sending emails only to addresses that are verified. The service also has an API platform that can be used by developers to integrate with other services that require email verification infrastructure.

26. SendPulse

SendPulse is a multi-channel marketing platform that also has a wide range of email-related services. The SendPulse API platform enables businesses to send bulk emails fast with high delivery rates. The API is designed to make it easier for developers to integrate the service with any application. The package comes in wrappers for many programming languages, including PHP, Python, Ruby, C#, Go, etc.

27. Neutrino API

Neutrino packages many data tools as APIs for developers. One of the most popular tools from Neutrino is the email validation tool. The API can be used to parse, validate, and clean email addresses. The service can be used to check compliance requirements and DNS validation.

28. QuickEmailVerification

QuickEmailVerification is another email verification tool available in API format. This helps in easy integration with any application. Using the service ensures that email marketing messages reach real prospective customers. It also helps to avoid email bounces and protect the server’s reputation.

29. Skrapp

Skrapp is an email outreach application for sales professionals. The service helps to find the real email addresses of business executives. It can be availed as a browser extension, web application, and also as an API. The REST API can be used to send bulk requests and has predictable URLs, a standard authentication process, and high security.

30. Verimail

Verimail is an email verification service that can be used to clean up address books. It supports high deliverability and a higher conversion rate at an extremely low cost. The real-time API can be used to bulk verify email addresses. You can test Verimail on a limited free trial before making a purchase decision.

31. ListWise

ListWise offers smart email marketing tools for businesses, including email verification tools that are available as an API. The service has a very high accuracy rate of more than 99%. The API enables easy integration with any application or platform.

32. DeBounce API

DeBounce is an enterprise-grade email validation service to avoid email bounces while sending mass emails. The API has extensive documentation and is easy to integrate and highly scalable. The API also can be set up to have different access levels based on different roles.

33. EmailLabs

The service offers a powerful API for sending emails. The API also assists in tracking the emails and performing marketing analytics on the tracked performance data. The API can be used to build separate tools for marketing emails and transactional emails. This makes sense as both the different kinds have different performance indicators to be assessed.

34. OxeBox API

OxeBox is a service for paperless billing receipts. The service has an API-oriented design that can be used by businesses to integrate with their digital infrastructure, enabling businesses to generate, retrieve, and cancel digital bills created by point-of-sale solutions. The API has extensive documentation and is very easy to integrate with existing platforms.

35. Trumail API

The Trumail API tests the veracity of email addresses to prevent bounced emails. This in turn helps in the upkeep of the email server’s reputation. The service has pretty straightforward API endpoints, giving developers an intuitive sense of the email verification API infrastructure.

36. Bouncer Email Verification API

Bouncer is an email verification and validation service that has a robust API for developers. The API is easy to set up and can handle bulk requests. Capable of real-time email verification, it’s suitable for use in live applications.

37. D7 LeadFinder

D7 LeadFinder is another lead-finding service that finds the accurate email addresses of prospective customers. This helps to avoid bounced emails and uphold the business’s email server reputation. The service accommodates bulk searches through its API. Filters and other attributes for search also can be applied programmatically.

38. Regulus Email Validator

Regulus helps to populate CRM applications with clean and verified data. It is a prominent complimentary application for Salesforce CRM. Regulus has API solutions for improving database quality and marketing campaigns. The API can be integrated with the CRM for email address validation and verification. The REST-based API is protected by 256-bit encryption to ensure data security.

39. Personator API

The service is focused only on the U.S. and Canada. It provides verification and enrichment API services for contact data including emails and physical addresses. This is made possible by leveraging billions of consumer records. This powerful API can be used to automate the validation of contact details and also for fraud detection.

40. Xverify API

The service offers intelligent email verification tools for all digital marketing requirements. The service helps to eliminate the hard bounce of emails, protect against fraud, and increase email deliverability. The service is also accessible with a robust API system maintained by Xverify. The API has extensive documentation, making it easier to integrate with any application.

41. Datafinder

Datafinder is used to find the contact data of online audiences to improve the performance and effectiveness of digital marketing campaigns. This is used as a supplement to other digital marketing tools like Facebook advertising and Google Adwords. One of Datafinder’s core features is the ability to append additional high-quality data to your customer list. The service is also accessible via a robust API framework.

42. MailboxValidator

MailboxValidator is a bulk email list cleaning service. The data can be uploaded in CSV or text format, and the application will clean up all the contact details in the data. The service can also be availed through an API, making it easy to integrate and use with existing applications. The output of API calls can be saved as JSON or XML files. Some of the API plans are free of charge for select users.

43. Global Email Web API

This is another API service from Melissa.com. The Global Email Web API service corrects and verifies the email addresses input to the API. Verifying emails with this service can improve email deliverability, prevent bounces, and avoid blacklisting of the mail servers. The service has a proprietary box-verification technology to gain the WHOIS information of the email domain to ensure the trustworthiness of emails.

44. Check-Mail Email Validation API

The service has a highly scalable solution for validating email addresses, and the API endpoints can also be used to detect disposable email addresses. The API’s different functions are geared towards protecting the reputation of the mail server from which marketing emails are delivered. The service also provides a score for each email based on a set of trust parameters. This helps to make the decision-making process simpler.

45. TempMail API

This tool is used to create temporary email addresses. Receiving spam messages is a problem when signing up for any service online. This can be countered by signing up with disposable email addresses. TempMail’s API infrastructure can be used to automate the creation of disposable email addresses.

46. MyEmailVerifier

MyEmailVerifier is a real-time JSON-based API service for verifying individual email addresses. The API gives the result as 5 levels of trust status, namely: valid, invalid, unknown, accept all, and grey-listed. This API can be used only for individual emails and not for bulk verification.

47. Nylas

Nylas is an email integration platform. It helps to form a direct connection with the inbox of users, providing real-time bi-directional sync capabilities. The API endpoints can also be used for the complete set of CRUD operations. The API is REST-based, and extensive documentation aids developers in easily integrating the service.

48. Emailable API

Emailable API is an email verification API that can be easily integrated with any website or application. The invalid email addresses can be filtered off right from the landing pages or applications. The API also supports batch operations and has support for webhooks. The client libraries are available in multiple programming languages.

49. NeverBounce

NeverBounce has a suite of services to avoid the hard bounce of emails. This helps to maintain the reputation of mail servers. Real-time email verification is one of the services offered as an API. The email addresses entered by users can be verified in real-time, right when emails are collected. The service can be easily integrated with various platforms, including the most popular email delivery platforms.

50. uProc

uProc offers data services that can be used to grow businesses with data optimization. The service also has a strong API infrastructure for email verification and validation. This service can be used to preserve mail server quality and prevent the hard bounce of marketing emails.

Managing email notifications as part of your overall notification strategy can be a challenge. MagicBell’s complete notification system offers an easy-to-implement notification inbox for your product and allows you to notify users wherever they are and how they prefer – without sending multiple notifications to the same user. With MagicBell’s extensible API, you can create and fetch notifications with clear error messages.