SMTP Services For Reliable Email Delivery

Send email when you don’t have your own mail server. Using an SMTP relay service like Mailgun is the simplest way to get started sending marketing and transactional emails.

Painless SMTP Server Setup

You need to send transactional emails and email marketing campaigns from your app or email client, but you want to make the process easy and painless. There are many options for SMTP service providers, but Mailgun offers some of the most flexible options available for a good SMTP server. With cloud-based SMTP services from Mailgun, you can send marketing emails and transactional emails to your entire mailing list without needing to support your own email server.

Our SMTP service provides:

  • real-time email tracking and advanced analytics for your emails
  • detailed logs to diagnose email delivery failures
  • increased deliverability features to reduce bounce rates and spam complaints
  • inbound email parsing and routing
  • email address validation services to improve your mailing list
  • easy integration with isp's like Gmail over TLS or SSL.

What Is An SMTP Server?

SMTP stands for Simple Mail Transfer Protocol and its primary purpose is to handle the sending, receiving, and relaying of email. Common inbox providers like Gmail have default smtp servers but you can change them to custom ones like Mailgun's. This will route your emails through Mailgun's servers which can be advantageous if you want to send a lot of emails and make sure it actually gets delivered into the inbox.

SMTP servers require authentication in the form of a username, password, smtp server address, ports, and what protocol (typically SSL or TLS). Mailgun provides you with all of the important details inside your account after you've added a domain to send from.

SMTP servers are an easy way to send email, but for even more efficiency you should use an email API. API's can process requests faster than a typical SMTP service, which can be a requirement for those looking to send millions of emails.

Email API Advanced Analytics

SMTP Relay

Using an SMTP relay service is the simplest way to get started sending emails. Add and verify your domain name, choose between a dedicated or shared IP address, and then set up your SMTP server. You only need four pieces of information: your username, password, the SMTP server host name, and the SMTP port. Add these into your application’s SMTP configuration settings, and you’re ready to send outgoing mail with Mailgun. Depending on which port you use, you can have either a regular or SSL connection to add security to your email.

Flexible Email API

If you don’t already have a third-party SMTP interface to drop Mailgun credentials into, consider using our HTTP API, which offers more flexibility and better scalability than the SMTP API. Its features give you easy control over your email delivery and email marketing services. Our libraries let developers work in their favorite languages, including Java, C#, Python, Ruby, and more.

Email API Analytics

Boost Deliverability

Increase your chances of email deliverability success with our SMTP relay and email service. Use SPF, DMARC, and DKIM record customization to authenticate your domain name. Add our email address validation API into your web forms to lower bounce rates and reduce spam complaints. And for a more proactive deliverability solution, our managed email delivery solution provides dedicated, one-on-one support and monitoring to boost your delivery rates even more.

Process Incoming Emails

Receive inbound messages fully parsed in UTF-8 format, with MIME converted to JSON. Mailgun’s email service lets you easily post email content to your application, automate reply handling, route spam into its own filter and more.


Track Email Events

Get detailed logs and metrics on marketing and transactional emails sent through Mailgun’s SMTP server and review specific email events like delivery failures, clicks, and unsubscribes through a simple control panel. Mailgun’s analytics help you analyze A/B tests, understand the effectiveness of your email campaigns, and boost your next send.

Sign Up Today

Integrate With Your Local Email Server

The best SMTP service offers useful benefits even if you have your own email server. Your application will see better performance because it hands off the sent emails to the local server, while your distribution still gets the benefit of a robust SMTP provider. The email server will handle any connectivity issues, letting you stay focused on application functionality, not error-handling.

Try our free plan to optimize your email delivery rates through the best SMTP services on the market today.

Sign Up Free
Check out our plans

to bundle together features for better deliverability. For businesses that send over 100,000 emails.

Other Features

Explore Beyond SMTP

Mailgun has a variety of features for companies in need of SMTP services.

sign up

It's easy to get started. And it's free.

See what you can accomplish with the world's best email delivery platform.

Sign Up For Free