# Source: https://documentation.mailgun.com/docs/mailgun/user-manual/smtp-protocol/smtp-protocol.md

# SMTP Protocol Introduction

In addition to the HTTP API, Mailgun servers also support the standard SMTP protocol. You can send email using SMTP with or without TLS.

You will need to refer to the standard library documentation for the language of your choice to learn how to you the SMTP protocol. Below are some links for a few popular languages:

- [Ruby SMTP](http://ruby-doc.org/stdlib/libdoc/net/smtp/rdoc/classes/Net/SMTP.html)
- [Python SMTP](http://docs.python.org/library/smtplib.html)
- [JavaMail API](http://java.sun.com/products/javamail/javadocs/index.html)