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How To Quickly Bake Mailgun With PHP

Orlando Kalossakas
5 min read

When I started coding, I remember debating whether I would want to learn ASP.NET vs PHP. I read thousands of bulletin boards on threads about each language to help me make my decision.

I chose PHP mainly for the community, the availability of examples and for the fact that it was open source. I’m sure these are similar reasons why you’ve chosen to adventure yourself in the world of PHP.

PHP is one of the most widely used languages, yet there is a lot of confusing or outdated material on the web.

The aim of this particular post is to provide you with a detailed overview on how to use Mailgun in your PHP environment with simple copy paste examples

Using the official Mailgun-PHP library

A very straightforward way to use Mailgun and leverage its outstanding API to deliver emails is to install the official PHP library in your development environment, written and maintained as an open source project by our Mailgunner Travis.


  • Open your terminal and navigate to your server’s public folder. This is where you store your website and varies depending on installation and web-server used - cd /var/www/html

  • Create an empty directory for this project - mkdir mailgun-php

  • Enter the directory and execute the following commands - cd mailgun-php (changes directory)

  • Now execute the following command to download and install Composer. - curl -sS https://getcomposer.org/installer | php

Composer, when used this way, allows us to download PHP libraries with ease locally within the folder. Now let’s use composer to install the Mailgun library itself.

  • Let’s run this to tell composer we’re going to use (and therefore we need it downloaded) the mailgun library (here we use 1.7.1) and its dependencies. - php composer.phar require mailgun/mailgun-php:~1.7.1

Congratulations, you’ve installed the Mailgun official library and you are now ready to write some code!

Open a file and include the vendor/autoload.phpfile to get started.

For example: (taken off the official documentation available here)

2require 'vendor/autoload.php';
3use Mailgun\Mailgun;
4//Your credentials
5$mg = new Mailgun("key-example");
6$domain = "example.com";
8//Customise the email - self explanatory
9$mg->sendMessage($domain, array(
11'to'=> 'sally@example.com',
12'subject' => 'The PHP SDK is awesome!',
13'text' => 'It is so simple to send a message.'
14 )

Using Swift Mailer

Using Mailgun with Swift Mailer is a breeze.

Make sure you have your domain’s SMTP credentials to hand! You can find these here they’re named:

  • Default SMTP Login

  • Default Password


  • Create a folder called Swiftmailer - mkdir swiftmailer, cd swiftmailer

  • Download Composer to install swiftmailer and its dependencies

    • curl -sS https://getcomposer.org/installer | php

  • Install Swiftmailer

    • php composer.phar require swiftmailer/swiftmailer @stable

  • Files will be downloaded, once finished simply create your own empty file to test that phpmailer works. Within your terminal you can achieve that by doing:

    • touch mailgun_with_swiftmailer.php

    • vim mailgun_with_swiftmailer.php

Here we’re using vim, but you can edit the file mailgun_with_swiftmailer.php in whichever editor you feel most comfortable with.

1require 'vendor/autoload.php';
3// Create the Transport
4$transport = Swift_SmtpTransport::newInstance('smtp.mailgun.org', 25)
5 ->setUsername('your SMTP username')
6 ->setPassword('your SMTP password')
7 ;
9// Create the Mailer using your created Transport
10$mailer = Swift_Mailer::newInstance($transport);
12// Create a message
13$message = Swift_Message::newInstance('Hello from Mailgun')
14 ->setFrom(array('someone@domain.com' => 'John Doe'))
15 ->setTo(array('someone_else@domain.org', 'third_contact@domain.org' => 'A third name'))
16 ->setBody("And that's another ace in the hole for the Mailgun dev!")
17 ;
19// Send the message
20$result = $mailer->send($message);

Further information on sending much more complicated emails can be found in the official Swiftmailer documentation available online over here.

Using PHP Mailer

Mailgun can also be used in conjunction with one of the most famous PHP emailing libraries: PHP Mailer.

PHP Mailer is a very valid alternative to the in-built php mail() function, as it speeds up and allows you to heavily customise the way you send emails with PHP. Linux distributions and Mac OS X have an in-built function to send emails although unreliable. By the way, it is worth mentioning that Windows hasn’t got anything at all to send emails, thus I suggest you keep reading.


  • Create a folder called phpmailer

    • mkdir phpmailer

    • cd phpmailer

  • Download composer to install phpmailer and its dependencies

    • curl -sS https://getcomposer.org/installer | php

  • Composer is ready, let’s install Phpmailer(5.2.8) now:

    • php composer.phar require phpmailer/phpmailer:5.2.8

  • Files will be downloaded, once finished simply create a your own empty file to test that phpmailer works

    • touch mailgun_with_phpmailer.php

    • vim mailgun_with_phpmailer.php

Here we’re using vim, but you can edit the file mailgun_with_phpmailer.php in whichever editor you feel most comfortable with.

2//Composer's autoload file loads all necessary files
3require 'vendor/autoload.php';
5$mail = new PHPMailer;
7$mail->isSMTP(); // Set mailer to use SMTP
8$mail->Host = 'smtp.mailgun.org'; // Specify mailgun SMTP servers
9$mail->SMTPAuth = true; // Enable SMTP authentication
10$mail->Username = 'username@domain.com'; // SMTP username from https://mailgun.com/cp/domains
11$mail->Password = 'myp@55w0rd'; // SMTP password from https://mailgun.com/cp/domains
12$mail->SMTPSecure = 'tls'; // Enable encryption, 'ssl'
14$mail->From = 'sender@domain.com'; // The FROM field, the address sending the email
15$mail->FromName = 'Orlie'; // The NAME field which will be displayed on arrival by the email client
16$mail->addAddress('recipient@domain.net', 'BOB'); // Recipient's email address and optionally a name to identify him
17$mail->isHTML(true); // Set email to be sent as HTML, if you are planning on sending plain text email just set it to false
19// The following is self explanatory
20$mail->Subject = 'Email sent with Mailgun';
21$mail->Body = '<span style="color: red">Mailgun rocks</span>, thank you <em>phpmailer</em> for making emailing easy using this <b>tool!</b>';
22$mail->AltBody = 'Mailgun rocks, shame you can't see the html sent with phpmailer so you're seeing this instead';
24if(!$mail->send()) {
25 echo "Message hasn't been sent.";
26 echo 'Mailer Error: ' . $mail->ErrorInfo . "n";
27} else {
28 echo "Message has been sent n";

The settings for authenticating with Mailgun’s SMTP server can be found over here, just like with Swiftmailer.

Log into your Mailgun control panel, pick a domain (or the sandbox domain that comes with every fresh account if you have not configured a custom domain), and copy paste these details (Default SMTP Login, Default Password) in the code snippet above in the smtp username and password fields.

Baking is awesome

Do you use other libraries in conjunction with Mailgun? If so we’d be happy to feature it in our next PHP blog post with full coverage and examples!

Happy Sending!


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Last updated on May 17, 2021

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