Reliable email delivery with industry-leading SMTP services

With Mailgun’s SMTP relay services, senders around the world can send both marketing and transactional emails alike without needing to manage their own mail servers.

SMTP sending made painless

Managing your own SMTP servers can be time-consuming and costly. Whether you’re looking to cut back on ownership costs or future-proof your email program, a cloud-based SMTP service is a great solution. Rather than footing the bill for things like hardware and maintenance, Mailgun takes care of the details by managing all of that internally and in-house so you can focus on your core business.

Alongside our SMTP servers, Mailgun provides:

  • Real-time email tracking and advanced analytics of your email program

  • Detailed logs to diagnose issues in sending

  • Advanced deliverability features to reduce bounce rates and spam complaints

  • Funnel incoming email messages easily with Inbound Routes

  • Email address verification services to improve your mailing list

  • Easy connection with MBPs like Gmail, Yahoo, and Outlook over TLS or SSL.

Illustration showing the API organization.
Illustration showing API code for email sending.

Understanding SMTP: what is an SMTP server?

A Simple Mail Transfer Protocol (SMTP) is a form of communication between servers used to send and receive email. SMTP servers require authentication in the form of a username, password, IP address, ports, and security protocol (typically SSL or TLS). Mailgun provides you with all of the important details inside your account after you've added and authenticated a domain name. From there, it’s easy to start sending via your application's SMTP email client. Need a little extra help? Consult our SMTP documentation.

While SMTP servers are an easy way to send outgoing mail, we recommend switching over to an Email API if your systems can support the migration. Email APIs can process requests faster than a typical SMTP service, and are easier to scale should your email volume be growing over time.

Send emails to the inbox

Secure your SMTP email streams and keep spammers from spoofing your brand with proper authentication protocols. With protocols like SPF, DMARC, and DKIM records, you’ll not only improve the reputation of your brand with recipients but with inbox service providers too. Using these methods alongside solutions like our email address Verifications, Inbox Placement tests, and Send Time Optimization lowers your spam rate, reduces spam complaints, and improves your overall email deliverability.

Need a more proactive approach and a helping hand? Our Deliverability Service pairs you with a Technical Account Manager who will advise you along the path to email sending success.

Easy to read incoming messages

Configure your SMTP setup and clean up your inbound email streams with routes. Routes allow senders to clean up cluttered email threads by fully parsing your inbound messages and converting them to UTF-8 for easy reading. Turn complex MIME data from incoming messages into straightforward JSON, making inbound processing a breeze for any business.

Illustration of email routes parsed into simple data.
Illustration of the analytics for an email campaign.

Analytics you can dive into

Understand every detail of what happened with your email with Mailgun’s log retention and email analytics. From the moment you send an email, you can track the journey your email takes to the inbox with log retention. No more waking up in the middle of the night to record message errors; get to them on your time.

Once your email reaches the inbox, you can track engagement metrics like opens and clicks to monitor email performance. Use hourly data to gain insight into recipient habits and understand campaign performance by digging into metrics like devices, location, and mailbox providers.

Pair with your local email server

An SMTP email service offers useful benefits even if you have your own email server. As a result of pairing an SMTP service with internal servers, 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. Whether you need to send one thousand or 10 million emails in minutes, Mailgun’s email infrastructure boasts 99.99% server uptime – so you’re never caught in a bind when you need it most.

Looking for a place to get started? Mailgun's documentation covers popular programming languages like Python, Ruby, Java, C# to make implementation as painless as possible.

Illustration showing an inbox being filtered by SPF, DKIM, and DMARC.
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