
If you need to send emails directly from your website, tools or backend process. An Email API is a good way to do it. There are multiple email service providers offering email APIs.
So in this article, I’m going to compare 11 of the best email API services out there.
11 Best Email API Overview
You may take sending and receiving emails for granted. But behind the scenes, email relies on an infrastructure of servers, relays, IP addresses and more. Email APIs let you plug it all straight into that email platform.
There are lots of benefits and potential uses for Email APIs. They are popular for sending transactional emails like receipts and order confirmations. For email marketing, APIs let you embed automated sending directly from your backend tools and website.
Short on time? Here’s a quick overview of the best email APIs:
Free Plan | Starting Price | Code libraries for | |
Brevo | Yes, 300 email / day | $15 for 20,000 | Node.js, PHP, Python, TypeScript, Java, C#, Go, Ruby |
SMTP.com | No | $25 for 50,000 | Not Available |
Mailtrap | Yes, 1000 email / month | $15 for 10,000 | Node.js, Ruby, PHP, Python, Elixir |
SMTP2GO | Yes, 1000 email / month | $10 for 10,000 | JavaScript, Node.js, PHP, Ruby, Python |
MailerSend | Yes | $24 for 50,000 | PHP, Node.js, Golang, Python, Ruby, Java, Laravel |
Mailgun | No | $35 /month 50K | Python, Ruby, Perl, Java, Go, C#, PHP, Node.js, Luvit |
Postmark | Yes, 100 email / month | $15 for 10,000 | Rails, Ruby, .NET, Java, PHP, Node.js, CLI |
SendGrid | Yes, 100 email / day | $19.95 for 50,000 | PHP, Python, Node.js, Java, C#, Go, Ruby |
Elastic Email | No | $19 for 50,000 | Ruby, Java, Go, PHP, C#, Python, JavaScript, Rust, Bash, Perl, Typescript Angular, Typescript Axios, Python |
SendPulse | Yes | $15 for 10,000 | PHP, Ruby, Python, Java, Node.js, C# |
What is an Email API?
An email API is a piece of code that connects software to send email through an external server. An application programming interface for email platforms. The API passes messages back and forth between them so they can communicate. Even if the softwares is coded in different languages, an API makes it work.
An email API connects to an email service provider. If an API is available, you don’t have to log in or use the normal interface. You add the API key in your platform or app. And then you can use the servers and email features to send emails based on website and software actions.
Email API vs SMTP
Email API and SMTP are often offered side-by-side by the same service providers. They are both ways to send email directly from the backend and connect to email infrastructure. Widely used for bulk sending and transactional emails directly from the backend.
So what is the difference?
SMTP | Email API | |
Definition | SMTP stands for Simple Mail Transfer Protocol. It’s one of the standards that allows email to work. Mail servers need SMTP to communicate with other servers. | An email API is a set of programming instructions and standards that allows software to communicate with an email service provider. Instead of configuring servers, developers can use API calls to send emails and track email performance. |
Pros | Simple to set up Easy for migration Simpler to troubleshoot | Reduces load on your servers More customizable Has error and retry mechanisms |
Cons | Slow performance for large volumes of email Delivery can be inconsistent | Steeper learning curve Need coding skills to troubleshoot |
SMTP servers were available long before email APIs became popular. They still provide a reliable way to add email sending to your stack. Connecting an SMTP server is also easier. Check out the best free SMTP servers to send emails at zero cost.
But an SMTP server comes pre-configured with fixed resources and capabilities. With email API, you get more scope to customize the server configuration. This gives you more control over things like deliverability and security.
What to Look for in an Email API Provider
Before I get to our top email API picks, here are the key things to look for from any provider.
- Ease of integration: Email APIs require some developer skills. And developers appreciate when tasks are straightforward like everyone else. Look for services that walk you through the setup process step by step. And have plenty of documentation and sandboxes for testing.
- Code libraries: APIs are built to connect software. But software is written in different programming languages. Check to see if an email API provider offers a code library in the language of your platform.
- RESTful APIs: REST is an architecture model for web applications. RESTful APIs are built in HTTP, the coding language of the internet. If you want to add email to any digital resource, you should look for a RESTful email API.
- Deliverability: Look for email APIs that actively work to protect and improve deliverability. Check for tools like sender reputation monitoring, email validation, inbox placement testing and authentication. Plus they should have a deliverability team.
- Customer service: There is a degree of technical difficulty involved with email APIs. You want to know you can get the support you need if something isn’t working correctly. Prioritise providers that offer phone and live chat support.
- Value for money: If email is critical to your business, avoid picking a service on price alone. Value for money is about judging what you get from a service versus its price. For example, reliable deliverability at higher volumes might cost more.
11 Best Email API Services in 2025
So that’s what we think makes a great email API service. But which providers do we think tick all the boxes? We’ve picked out our top 10. They range from email marketing and transactional email platforms to specialist email delivery platforms.
1. Brevo

Brevo made its name as an email marketing platform. It has always offered an API for transactional emails. And these days, you can use the API for marketing campaigns as well.
Brevo’s RESTful API gives you access to their SMTP server infrastructure. This supports high deliverability rates and rapid sending speeds. The Brevo infrastructure can handle 120,000 emails a minute per client. Every email sent is logged, with analytical tools to monitor performance.
The API comes with ready-to-go libraries for Node.js, PHP, Python, TypeScript, Java, C#, Go, and Ruby.
There is also full technical guidance on how to build and send email campaigns via the API. A big benefit is that you get access to Brevo’s email-building and automation tools. You can design and personalize emails with its user-friendly drag-and-drop editor. There are good quality templates start with. And you can set custom triggers for how and when emails are sent.
Brevo Pros
- API suitable for marketing campaigns and transactional emails
- Drag-and-drop email builder and templates
- Automation builder and customizable triggers
- Libraries for most major programming languages
- Send 300 emails a day for free
Brevo Cons
- Email-only support
Pricing starts at $15 for 20,000 emails a month. Its free plan is one of the most generous around. You can send 300 emails a day for no charge.
Try Brevo for free here or read our full review
2. SMTP.com

SMTP.com is an email relay service. It offers a highly scalable cloud-based server infrastructure accessed via a RESTful API.
SMTP.com is built for bulk sending at high volumes. Monthly plans start at 50,000, and custom plans have minimum 250 million monthly emails.
At those scales, you must have a strong and reliable infrastructure. SMTP.com promises 99% systems uptime and 98% deliverability rates. This is an excellent number at very high volumes.
High deliverability rates depend on a solid sender reputation. SMTP.com has built that over 22 years with quality deliverability tools. Automated email validation vets email addresses before you send. This reduces the number of bounces you get.
SMTP.com’s API is programmed to make integration into other platforms as easy as possible. It has full documentation for authentication, API keys, and DKIM setup. Migration templates for most major email relay and API providers make it easy to switch to SMTP.com.
There are no tools for creating emails in SMTP.com. You have to connect to another platform. Check out our review of the best drag-and-drop email editors to find the right tool.
SMTP.com Pros
- Excellent deliverability rates
- Scalable up to the highest bulk-sending volumes
- Automated email validation
- Simple integration supported by extensive documentation
- Phone and live chat support
SMTP.com Cons
- It doesn’t publish its own code libraries. But there are third-party libraries recommended.
Pricing starts at $25 a month for 50,000 emails. For $80 a month you get a dedicated IP address and can send 100,000 emails.
Get started with SMTP.com for free
3. Mailtrap

Mailtrap is an email delivery platform with email testing, email marketing, and an email API and SMTP service.
Mailtrap’s RESTful API has excellent documentation. Official SDKs are available for NodeJS, Ruby, PHP, Python, and Elixir. But you can still use it with any programming language that allows HTTP requests.
Email authentication is automatic with the Mailtrap API and they rotate DKIM keys monthly for added security.
You can create email templates with a code editor and the drag-and-drop email builder. The email editor gets the job done, but we’ve seen better. And there are only 2 templates.
To make sure there aren’t any issues in your emails before sending, you can inspect them in a safe sandbox environment. It also comes with email logs to troubleshoot sending issues. The spam checker makes sure your IP isn’t blacklisted and you’re good to send.
Mailtrap has a deliverability team to assist you with migration, and setup. With a custom plan, you can even get a deliverability manager.
Mailtrap Pros
- User-friendly interface
- Weekly deliverability summaries
- Safe sandbox environment for testing
- Deliverability team and manager
- Free plan with 1000 emails and 500 contacts
Mailtrap Cons
- Doesn’t have email verification
- Only 2 basic email templates for welcome and promo emails
Mailtrap Email API pricing starts at $15/month for 10K emails. Mailtrap has free plans for the Email API/SMTP with 500 contacts, 1000 emails, email logs, 100 email tests, API key permissions, and 24/7 support.
4. SMTP2GO

SMTP2GO is another SMTP-based sending service with a big focus on deliverability. Its developer-friendly API gives you access to a global sending infrastructure. It has in-depth analytics into every email sent. And improves deliverability with inbox testing.
SMTP2GO guarantees 100% uptime for its servers. That’s not something you see too often with email services. It can do that because it runs a distributed network of servers across North America, Europe, and Asia. This means if one server goes down, another picks up the slack. So your emails always send, no matter if there are local outages or not. Another benefit is that you can choose the location of your primary servers. And get faster delivery from local data centres.
Talking of deliverability, SMTP2GO offers inbox testing for 40 different email clients. This tells you how likely your emails are to pass different spam filters. It also shows how your emails look in different inboxes. SMTP2GO doesn’t offer any tools for building emails. But this is a useful tool to connect to your preferred email builder. It flags up any issues with email services before you hit send.
The API comes with published libraries for JavaScript, Node.js, PHP, Ruby and Python. Real-time support is available 24/7 worldwide via phone, live chat, and an online help desk.
SMTP2GO Pros
- 100% email server uptime guarantee
- Global infrastructure for fast local sending
- Spam folder and inbox sending for 40+ email clients
- Status reports for every email sent
- Free plan
SMTP2Go Cons
- The per-email cost works out higher than many rival services
Pricing starts at $10 a month with 10,000 emails included. There is a free plan which includes 1,000 emails. You can send a maximum of 200 emails a day on the free plan.
5. MailerSend

MailerSend is an SME-friendly transactional email service. The drag-and-drop editor makes designing your transactional templates simple. Its API is easy to integrate into the platforms you want to send emails from. It’s also affordably priced and offers email validation to help improve deliverability.
MailerSend’s email API comes with full documentation. It has libraries in PHP, Node.js, Golang, Python, Ruby, Java, and Laravel. You can send attachments, send in bulk, and personalize emails. There’s also an inbound routing option for handling incoming emails.
MailerSend stands out for having not one but three ways to create emails. There’s the standard drag-and-drop editor for HTML emails. There are fully customizable templates for pretty much every type of transactional email. All templates support dynamic content for personalization.
There’s also a Rich Text editor for simple text-only emails. Or if you fancy coding your own templates, there’s a dedicated HTML editor. The great thing about this is you can see your template as you code.
MailerSend also offers an email verification API. This lets you check email addresses as you get new subscribers in your app. There’s also a bulk verification option.
MailerSend Pros
- Extensive API code library
- Multiple options for creating emails
- Email verification API
- Dedicated IP address on all paid accounts
- Free plan
MailerSend Cons
- No phone support, just 24/7 live chat
Pricing starts at $24 a month for 50,000 emails. This also includes 100 email verifications. There is a free plan that lets you send 3,000 emails a month.
6. Mailgun

Mailgun is a feature-rich email sending platform aimed squarely at developers. It has APIs for email sending, tracking and analytics, email validation, and templates. There’s a drag-and-drop builder for creating transactional and marketing emails. The Templates API allows you to configure and store templates in your own platform. And there are tools for performance optimization and deliverability.
Mailgun offers some of the most comprehensive API documentation out there. That includes a code library covering Python, Ruby, Perl, Java, Go, C#, PHP, Node.js, and Luvit.
Mailgun’s server infrastructure is built in the Google Cloud. That allows it to combine scalability with high reliability. It offers a 99.99% uptime guarantee. And plans go up to 2.5m+ emails a month.
Mailgun’s Events API tracks and logs detailed information about every email sent. It then applies in-depth analytics to inform users how to improve deliverability. Mailgun Optimize includes inbox placement testing, email address validation, and blocklist and reputation monitoring. You can also preview how your email will appear in different clients. Read our full Mailgun review to find out more about its features and pricing.
Mailgun Pros
- Full API documentation and code libraries for 9 languages
- Inbox placement testing and email validation
- Advanced analytics
- Phone and live chat support
Mailgun Cons
- More expensive than some rival services
Pricing for Mailgun Send starts at $35 per month with 50,000 emails a month via the email API or SMTP relay. Mailgun Optimize starts at $49 per month. This includes 2,500 email address validations and 25 inbox placement tests.
7. Postmark

Postmark is an email delivery service owned by ActiveCampaign. It offers sending infrastructure for marketing and transactional emails. You can also design and build emails in Postmark.
Postmark’s RESTful API comes with excellent documentation. It provides code libraries for Rails, Ruby, .NET, Java, PHP, Node.js, and CLI. Plus, it publishes links to community libraries for 20+ other languages. There are also plug-ins for WordPress, Grunt, Craft, and Google Go. These are backed up with extensive user guides to make developers’ lives easier.
Postmark also makes a big deal about send time. Or ‘time-to-inbox’. It publishes stats for delivery speeds to every major inbox on its home page. Why? Because slow delivery can lead to missed revenue. Or indicate problems with servers. Postmark actively monitors both. And shows you when it thinks there’s an issue.
Postmark offers responsive templates for transactional emails. You can edit and customize them in the platform or build your own from scratch. Postmark doesn’t have email verification. If you choose Postmark and have a large email list, check out our review of the best email verification tools.
Postmark Pros
- Developer-friendly documentation and libraries
- Separate sending environments for transactional and broadcast emails
- Rapid inbox delivery
- Ready-made and code-your-own transactional templates
- Detailed tracking and data retention
Postmark Cons
- Support by email ticket only
Pricing starts at $15 a month for 10,000 emails. There’s a free tier that includes 100 emails a month.
8. SendGrid

SendGrid positions itself as an email platform for both developers and marketers. On the developer side, that means an email API. For marketers, that means email marketing tools. The two are offered as separate products. But there are useful crossovers. For example, the API borrows the HTML template editor from the email marketing tool. And you can trigger automated email campaigns from any platform you choose.
SendGrid’s email API gives you access to a mail transfer agent (MTA). Built for high-volume sending, it delivers over 100 billion emails every month. SendGrid claims 99.99% uptime with median delivery speeds of 1.9 seconds.
There are tools for email validation, sender authentication and suppression list monitoring. Throttle threat detection, queue optimization and automatic resending take deliverability up a notch. In short, if there are any network issues why an email might bounce, SendGrid takes care of it.
SendGrid says they work proactively with major email clients like Gmail, Microsoft Outlook and Yahoo. All to keep deliverability to those inboxes high. Not surprisingly, that’s what everybody says, so you can discard that. Nobody has a direct line.
As for using the API, SendGrid claims typical integrations take five minutes. There are detailed guides for setting up cURL, building an API call and using an API key. SendGrid offers code libraries for PHP, Python, Node.js, Java, C#, Go and Ruby.
SendGrid Pros
- Fast, reliable performance at high sending volumes
- Active network performance monitoring
- Email builder included with the API
- Free plan
SendGrid Cons
- Phone support is only available on higher plans if you request a callback
SendGrid plans start at $19.95 a month for 50,000 emails. There is a free tier that lets you send 100 emails a day.
Try SendGrid or find the best SendGrid alternatives here
9. Elastic Email

Elastic Email offers a developer-friendly API centred on a custom-built MTA. This improves deliverability rates, but it still works out as one of the cheapest email APIs.
Having its own MTA gives Elastic Email complete control over deliverability. It handles all domain authentication directly to prevent account spoofing. It can manage send volumes so spam filters don’t get spooked. This happens in two ways. IP warm-up gradually increases send volumes so spam filters ‘get used’ to activity. Throttling means capping send volumes according to known inbox receiving limits. And email verification is also included in all plans.
On the set-up side, Elastic Email offers one of the biggest code libraries of any email API. There are 12 languages, including Ruby, Java, Go, PHP and C#, Python and JavaScript. Configuration and technical management are supported by documentation.
Aside from the API, Elastic Email offers 20+ pre-configured plugins. There are plugins for popular CMS software like WordPress, Drupal, Joomla and WooCommerce. This makes adding email to a website or ecommerce store accessible for non-developers.
Elastic Email also offers email marketing as a stand-alone product. But its HTML email builder and transactional templates come with the API.
Elastic Email Pros
- Low cost-per-email
- Advanced sender reputation protections
- Code libraries for 12 programming languages
- CMS plugins for easy integration
- Email builder and templates
Elastic Email Cons
- No free tier
Pricing for Elastic Email’s API starts at $19 a month for 50,000 emails.
Get started with Elastic Email here
10. SendPulse

SendPulse is a solid email service for both email marketing and transactional email. The SendPulse email API ticks most of the boxes you would expect. It’s RESTful. It offers developers code libraries in PHP, Ruby, Python, Java, Node.js and C#. Plus there are links to recommended third-party libraries in GitHub.
All paid-for transactional email plans come with a dedicated IP address. On most rival services, you either have to pay more for a dedicated IP. Or upgrade to higher plans. Dedicated IP addresses mean no one else is sending from the same environment as you. You can’t have your sender reputation hurt by the poor practices of others.
SendPulse Pros
- Send 12,000 emails a month for free
- Dedicated IP address on all paid plans
- Automatically blocks sending to unsubscribed email addresses
- Wide choice of marketing tools to run from the same platform
- Flexible pricing
SendPulse Cons
- Lacks the deliverability management features a lot of email APIs offer.
SendPulse pricing is very flexible. It has both subscription and pay-as-you-go options. Transactional email subscriptions start at $59.88 a month for 100,000 emails. Or you can pay $15 per 10,000 emails pay-as-you-go.
Where SendPulse really stands out value-wise is that you can send 12,000 emails for free. That’s about the best free deal on email APIs available.
11. Amazon SES

Amazon Simple Email Service (SES) is built on Amazon’s huge cloud infrastructure. Amazon SES handles more than a trillion emails a year. It’s used by some of the world’s biggest email senders, including Amazon Retail and Netflix. And it has a unique cost structure that makes it highly scalable.
Amazon SES can be the logical choice if you work in AWS environments. Not surprisingly, it’s built to fully integrate with the Amazon EC2 cloud. You can manage the hosting server and SES from one dashboard.
Amazon doesn’t publish any code libraries for HTTPS requests. It offers software development kits (SDKs) in multiple languages. The SDKs provide deeper root access to the Amazon platform. You can also access the API via the AWS Command Line Interface.
There’s a choice of shared, dedicated and ‘bring your own’ IP address deployments. Amazon also offers a managed option for its dedicated servers.
SES offers 3 main tools for deliverability management. The Virtual Deliverability Manager uses analytics to make deliverability recommendations. You can also set it up to automate improvements. The Reputation Dashboard tracks things like bounces and recipient complaints. And the Mailbox Simulator is the sandbox environment to test your email deployments and responses.
Amazon SES Pros
- Flexible configuration and deployment options
- Full suite of deliverability tools
- Pay-as-you-go pricing
- Free tier with generous send limits
Amazon SES Cons
- Limited customer support, online knowledge base and general AWS technical support only
Amazon SES charges a flat rate of $0.10 per 1000 emails sent. There are various add-ons to this, including $0.12 per GB of attachments. There is a free tier that lets you send 3,000 emails a month.
Try Amazon SES or find the best Amazon SES alternatives here
Concluding Email APIs
There’s more than one good reason to use an email API. They allow you to manage email from your own platforms. They’re designed for bulk sending at high volumes. They offer tools to help you get optimal inbox placement.
Choosing the best email API is about matching the right features to your business needs. Are high sending volumes most important to you? Deliverability and reliability? Price? Developer support tools? In truth, you’re likely to want a good balance of all of these things.
FAQs about Email API
What is the best email API?
SendGrid and Postmark offer outstanding deliverability features. Elastic Email and Amazon SES are both great value. MailerSend is a good option for SMEs. SMTP.com and SMTP2GO are among the best bulk email services for high sending volumes. Brevo is the best choice if you want to focus on marketing emails.
Is there a free email API?
What is the cheapest email API service?
Out of email APIs that charge a subscription fee, Elastic Email is the cheapest. $19 a month for 50,000 emails works out at $0.00038 per email.
How do I send an email using API?
The API key gives another software access to the service’s email-sending infrastructure. From there, you can send emails in various ways. You can set up triggers to automatically send transactional emails. You can connect to contact databases to send bulk emails. Some email APIs offer tools for creating emails. Others are ‘send only’. So you have to connect to an email editor, too.