mailer.rst

Sending Emails with Mailer

Installation

Symfony's Mailer & Mime </components/mime> components form a powerful system for creating and sending emails - complete with support for multipart messages, Twig integration, CSS inlining, file attachments and a lot more. Get them installed with:

$ composer require symfony/mailer

Transport Setup

Emails are delivered via a "transport". And without installing anything else, you can deliver emails over smtp by configuring your .env file:

# .env
MAILER_DSN=smtp://user:pass@smtp.example.com

Warning

If you are migrating from Swiftmailer (and the Swiftmailer bundle), be warned that the DSN format is different.

Using a 3rd Party Transport

But an easier option is to send emails via a 3rd party provider. Mailer supports several - install whichever you want:

Service	Install with
Amazon SES	composer require symfony/amazon-mailer
Gmail	composer require symfony/google-mailer
MailChimp	composer require symfony/mailchimp-mailer
Mailgun	composer require symfony/mailgun-mailer
Postmark	composer require symfony/postmark-mailer
SendGrid	composer require symfony/sendgrid-mailer

Each library includes a Symfony Flex recipe <symfony-flex> that will add example configuration to your .env file. For example, suppose you want to use SendGrid. First, install it:

$ composer require symfony/sendgrid-mailer

You'll now have a new line in your .env file that you can uncomment:

# .env
SENDGRID_KEY=
MAILER_DSN=smtp://$SENDGRID_KEY@sendgrid

The MAILER_DSN isn't a real SMTP address: it's a simple format that offloads most of the configuration work to mailer. The @sendgrid part of the address activates the SendGrid mailer library that you just installed, which knows all about how to deliver messages to SendGrid.

The only part you need to change is to set SENDGRID_KEY to your key (in .env or .env.local).

Each transport will have different environment variables that the library will use to configure the actual address and authentication for delivery. Some also have options that can be configured with query parameters on end of the MAILER_DSN -like ?region= for Amazon SES. Some transports support sending via http or smtp - both work the same, but http is recommended when available.

Tip

Check the DSN formats <mailer_dsn> for all supported providers.

Creating & Sending Messages

To send an email, autowire the mailer using Symfony\\Component\\Mailer\\MailerInterface (service id mailer) and create an Symfony\\Component\\Mime\\Email object:

// src/Controller/MailerController.php
namespace App\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
use Symfony\Component\Mailer\MailerInterface;
use Symfony\Component\Mime\Email;

class MailerController extends AbstractController
{
    /**
     * @Route("/email")
     */
    public function sendEmail(MailerInterface $mailer)
    {
        $email = (new Email())
            ->from('hello@example.com')
            ->to('you@example.com')
            //->cc('cc@example.com')
            //->bcc('bcc@example.com')
            //->replyTo('fabien@example.com')
            //->priority(Email::PRIORITY_HIGH)
            ->subject('Time for Symfony Mailer!')
            ->text('Sending emails is fun again!')
            ->html('<p>See Twig integration for better HTML integration!</p>');

        $mailer->send($email);

        // ...
    }
}

That's it! The message will be sent via whatever transport you configured.

Email Addresses

All the methods that require email addresses (from(), to(), etc.) accept both strings or address objects:

// ...
use Symfony\Component\Mime\Address;

$email = (new Email())
    // email address as a simple string
    ->from('fabien@example.com')

    // email address as an object
    ->from(new Address('fabien@example.com'))

    // defining the email address and name as an object
    // (email clients will display the name)
    ->from(new Address('fabien@example.com', 'Fabien'))

    // defining the email address and name as a string
    // (the format must match: 'Name <email@example.com>')
    ->from(Address::fromString('Fabien Potencier <fabien@example.com>'))

    // ...
;

Multiple addresses are defined with the addXXX() methods:

$email = (new Email())
    ->to('foo@example.com')
    ->addTo('bar@example.com')
    ->addTo('baz@example.com')

    // ...
;

Alternatively, you can pass multiple addresses to each method:

$toAddresses = ['foo@example.com', new Address('bar@example.com')];

$email = (new Email())
    ->to(...$toAddresses)
    ->cc('cc1@example.com', 'cc2@example.com')

    // ...
;

Message Contents

The text and HTML contents of the email messages can be strings (usually the result of rendering some template) or PHP resources:

$email = (new Email())
    // ...
    // simple contents defined as a string
    ->text('Lorem ipsum...')
    ->html('<p>Lorem ipsum...</p>')

    // attach a file stream
    ->text(fopen('/path/to/emails/user_signup.txt', 'r'))
    ->html(fopen('/path/to/emails/user_signup.html', 'r'))
;

Tip

You can also use Twig templates to render the HTML and text contents. Read the Twig: HTML & CSS section later in this article to learn more.

File Attachments

Use the attachFromPath() method to attach files that exist on your file system:

$email = (new Email())
    // ...
    ->attachFromPath('/path/to/documents/terms-of-use.pdf')
    // optionally you can tell email clients to display a custom name for the file
    ->attachFromPath('/path/to/documents/privacy.pdf', 'Privacy Policy')
    // optionally you can provide an explicit MIME type (otherwise it's guessed)
    ->attachFromPath('/path/to/documents/contract.doc', 'Contract', 'application/msword')
    // you can also use an absolute URL if your PHP config allows getting URLs using fopen()
    // (this is not recommended because your application may or may not work depending on PHP config)
    ->attachFromPath('http://example.com/path/to/documents/contract.doc', 'Contract', 'application/msword')
;

Alternatively you can use the attach() method to attach contents from a stream:

$email = (new Email())
    // ...
    ->attach(fopen('/path/to/documents/contract.doc', 'r'))
;

Embedding Images

If you want to display images inside your email, you must embed them instead of adding them as attachments. When using Twig to render the email contents, as explained later in this article, the images are embedded automatically. Otherwise, you need to embed them manually.

First, use the embed() or embedFromPath() method to add an image from a file or stream:

$email = (new Email())
    // ...
    // get the image contents from a PHP resource
    ->embed(fopen('/path/to/images/logo.png', 'r'), 'logo')
    // get the image contents from an existing file
    ->embedFromPath('/path/to/images/signature.gif', 'footer-signature')
;

The second optional argument of both methods is the image name ("Content-ID" in the MIME standard). Its value is an arbitrary string used later to reference the images inside the HTML contents:

$email = (new Email())
    // ...
    ->embed(fopen('/path/to/images/logo.png', 'r'), 'logo')
    ->embedFromPath('/path/to/images/signature.gif', 'footer-signature')
    // reference images using the syntax 'cid:' + "image embed name"
    ->html('<img src="cid:logo"> ... <img src="cid:footer-signature"> ...')
;

Global from Address

Instead of calling ->from() every time you create a new email, you can create an event subscriber to set it automatically:

// src/EventSubscriber/MailerFromSubscriber.php
namespace App\EventSubscriber;

use Symfony\Component\EventDispatcher\EventSubscriberInterface;
use Symfony\Component\Mailer\Event\MessageEvent;
use Symfony\Component\Mime\Email;

class MailerFromSubscriber implements EventSubscriberInterface
{
    public function onMessageSend(MessageEvent $event)
    {
        $message = $event->getMessage();

        // make sure it's an Email object
        if (!$message instanceof Email) {
            return;
        }

        // always set the from address
        $message->from('fabien@example.com');
    }

    public static function getSubscribedEvents()
    {
        return [MessageEvent::class => 'onMessageSend'];
    }
}

Twig: HTML & CSS

The Mime component integrates with the Twig template engine </templating> to provide advanced features such as CSS style inlining and support for HTML/CSS frameworks to create complex HTML email messages. First, make sure Twig is installed:

$ composer require symfony/twig-bundle

HTML Content

To define the contents of your email with Twig, use the Symfony\\Bridge\\Twig\\Mime\\TemplatedEmail class. This class extends the normal Symfony\\Component\\Mime\\Email class but adds some new methods for Twig templates:

use Symfony\Bridge\Twig\Mime\TemplatedEmail;

$email = (new TemplatedEmail())
    ->from('fabien@example.com')
    ->to(new Address('ryan@example.com', 'Ryan'))
    ->subject('Thanks for signing up!')

    // path of the Twig template to render
    ->htmlTemplate('emails/signup.html.twig')

    // pass variables (name => value) to the template
    ->context([
        'expiration_date' => new \DateTime('+7 days'),
        'username' => 'foo',
    ])
;

Then, create the template:

{# templates/emails/signup.html.twig #}
<h1>Welcome {{ email.toName }}!</h1>

<p>
    You signed up as {{ username }} the following email:
</p>
<p><code>{{ email.to[0].address }}</code></p>

<p>
    <a href="#">Click here to activate your account</a>
    (this link is valid until {{ expiration_date|date('F jS') }})
</p>

The Twig template has access to any of the parameters passed in the context() method of the TemplatedEmail class and also to a special variable called email, which is an instance of Symfony\\Bridge\\Twig\\Mime\\WrappedTemplatedEmail.

Text Content

When the text content of a TemplatedEmail is not explicitly defined, mailer will generate it automatically by converting the HTML contents into text. If you have league/html-to-markdown installed in your application, it uses that to turn HTML into Markdown (so the text email has some visual appeal). Otherwise, it applies the strip_tags PHP function to the original HTML contents.

If you want to define the text content yourself, use the text() method explained in the previous sections or the textTemplate() method provided by the TemplatedEmail class:

+ use Symfony\Bridge\Twig\Mime\TemplatedEmail;

$email = (new TemplatedEmail())
    // ...

    ->htmlTemplate('emails/signup.html.twig')
+     ->textTemplate('emails/signup.txt.twig')
    // ...
;

Embedding Images

Instead of dealing with the <img src="cid: ..."> syntax explained in the previous sections, when using Twig to render email contents you can refer to image files as usual. First, to simplify things, define a Twig namespace called images that points to whatever directory your images are stored in:

# config/packages/twig.yaml
twig:
    # ...

    paths:
        # point this wherever your images live
        '%kernel.project_dir%/assets/images': images

Now, use the special email.image() Twig helper to embed the images inside the email contents:

{# '@images/' refers to the Twig namespace defined earlier #}
<img src="{{ email.image('@images/logo.png') }}" alt="Logo">

<h1>Welcome {{ email.toName }}!</h1>
{# ... #}

Inlining CSS Styles

Designing the HTML contents of an email is very different from designing a normal HTML page. For starters, most email clients only support a subset of all CSS features. In addition, popular email clients like Gmail don't support defining styles inside <style> ... </style> sections and you must inline all the CSS styles.

CSS inlining means that every HTML tag must define a style attribute with all its CSS styles. This can make organizing your CSS a mess. That's why Twig provides a CssInlinerExtension that automates everything for you. Install it with:

$ composer require twig/cssinliner-extension

The extension is enabled automatically. To use this, wrap the entire template with the inline_css filter:

{% apply inline_css %}
    <style>
        {# here, define your CSS styles as usual #}
        h1 {
            color: #333;
        }
    </style>

    <h1>Welcome {{ email.toName }}!</h1>
    {# ... #}
{% endapply %}

Using External CSS Files

You can also define CSS styles in external files and pass them as arguments to the filter:

{% apply inline_css(source('@css/email.css')) %}
    <h1>Welcome {{ username }}!</h1>
    {# ... #}
{% endapply %}

You can pass unlimited number of arguments to inline_css() to load multiple CSS files. For this example to work, you also need to define a new Twig namespace called css that points to the directory where email.css lives:

# config/packages/twig.yaml
twig:
    # ...

    paths:
        # point this wherever your css files live
        '%kernel.project_dir%/assets/css': css

Rendering Markdown Content

Twig provides another extension called MarkdownExtension that lets you define the email contents using Markdown syntax. To use this, install the extension and a Markdown conversion library (the extension is compatible with several popular libraries):

# instead of league/commonmark, you can also use erusev/parsedown or michelf/php-markdown
$ composer require twig/markdown-extension league/commonmark

The extension adds a markdown filter, which you can use to convert parts or the entire email contents from Markdown to HTML:

{% apply markdown %}
    Welcome {{ email.toName }}!
    ===========================

    You signed up to our site using the following email:
    `{{ email.to[0].address }}`

    [Click here to activate your account]({{ url('...') }})
{% endapply %}

Inky Email Templating Language

Creating beautifully designed emails that work on every email client is so complex that there are HTML/CSS frameworks dedicated to that. One of the most popular frameworks is called Inky. It defines a syntax based on some simple tags which are later transformed into the real HTML code sent to users:

<!-- a simplified example of the Inky syntax -->
<container>
    <row>
        <columns>This is a column.</columns>
    </row>
</container>

Twig provides integration with Inky via the InkyExtension. First, install the extension in your application:

$ composer require twig/inky-extension

The extension adds an inky filter, which can be used to convert parts or the entire email contents from Inky to HTML:

{% apply inky %}
    <container>
        <row class="header">
            <columns>
                <spacer size="16"></spacer>
                <h1 class="text-center">Welcome {{ email.toName }}!</h1>
            </columns>

            {# ... #}
        </row>
    </container>
{% endapply %}

You can combine all filters to create complex email messages:

{% apply inky|inline_css(source('@css/foundation-emails.css')) %}
    {# ... #}
{% endapply %}

This makes use of the css Twig namespace <mailer-css-namespace> we created earlier. You could, for example, download the foundation-emails.css file directly from GitHub and save it in assets/css.

Signing and Encrypting Messages

It's possible to sign and/or encrypt email messages applying the S/MIME standard to increase their integrity/security. Both options can be combined to encrypt a signed message and/or to sign an encrypted message.

Before signing/encrypting messages, make sure to have:

• The OpenSSL PHP extension properly installed and configured;
• A valid security certificate (you can get it for free from Let's Encrypt project).

Signing Messages

When signing a message, a cryptographic hash is generated for the entire content of the message (including attachments). This hash is added as an attachment so the recipient can validate the integrity of the received message. However, the contents of the original message are still readable for mailing agents not supporting signed messages, so you must also encrypt the message if you want to hide its contents:

use Symfony\Component\Mime\Crypto\SMimeSigner;
use Symfony\Component\Mime\Email;

$email = (new Email())
    ->from('hello@example.com')
    // ...
    ->html('...');

$signer = new SMimeSigner('/path/to/certificate.crt', '/path/to/certificate-private-key.key');
// if the private key has a passphrase, pass it as the third argument
// new SMimeSigner('/path/to/certificate.crt', '/path/to/certificate-private-key.key', 'the-passphrase');

$signedEmail = $signer->sign($email);
// now use the Mailer component to send this $signedEmail instead of the original email

The certificate and private key must be PEM encoded, and can be either created using for example OpenSSL or obtained at an official Certificate Authority (CA). The email recipient must have the CA certificate in the list of trusted issuers in order to verify the signature.

Tip

When using OpenSSL to generate certificates, make sure to add the -addtrust emailProtection command option.

Tip

The SMimeSigner class defines other optional arguments to pass intermediate certificates and to configure the signing process using a bitwise operator options for openssl_pkcs7_sign PHP function.

Encrypting Messages

When encrypting a message, the entire message (including attachments) is encrypted using a certificate. Therefore, only the recipients that have the corresponding private key can read the original message contents:

use Symfony\Component\Mime\Crypto\SMimeEncrypter;
use Symfony\Component\Mime\Email;

$email = (new Email())
    ->from('hello@example.com')
    // ...
    ->html('...');

$encrypter = new SMimeEncrypter('/path/to/certificate.crt');
$encryptedEmail = $encrypter->encrypt($email);
// now use the Mailer component to send this $encryptedEmail instead of the original email

You can pass more than one certificate to the SMimeEncrypter() constructor and it will select the appropriate certificate depending on the To option:

$firstEmail = (new Email())
    // ...
    ->to('jane@example.com');

$secondEmail = (new Email())
    // ...
    ->to('john@example.com');

$encrypter = new SMimeEncrypter([
    // key = email recipient; value = path to the certificate file
    'jane@example.com' => '/path/to/first-certificate.crt',
    'john@example.com' => '/path/to/second-certificate.crt',
]);

$firstEncryptedEmail = $encrypter->encrypt($firstEmail);
$secondEncryptedEmail = $encrypter->encrypt($secondEmail);

Sending Messages Async

When you call $mailer->send($email), the email is sent to the transport immediately. To improve performance, you can leverage Messenger </messenger> to send the messages later via a Messenger transport.

Start by following the Messenger </messenger> documentation and configuring a transport. Once everything is set up, when you call $mailer->send(), a Symfony\\Component\\Mailer\\Messenger\\SendEmailMessage message will be dispatched through the default message bus (messenger.default_bus). Assuming you have a transport called async, you can route the message there:

# config/packages/messenger.yaml
framework:
    messenger:
        transports:
            async: "%env(MESSENGER_TRANSPORT_DSN)%"

        routing:
            'Symfony\Component\Mailer\Messenger\SendEmailMessage':  async

<!-- config/packages/messenger.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<container xmlns="http://symfony.com/schema/dic/services"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:framework="http://symfony.com/schema/dic/symfony"
    xsi:schemaLocation="http://symfony.com/schema/dic/services
        https://symfony.com/schema/dic/services/services-1.0.xsd
        http://symfony.com/schema/dic/symfony
        https://symfony.com/schema/dic/symfony/symfony-1.0.xsd">

    <framework:config>
        <framework:messenger>
            <framework:routing message-class="Symfony\Component\Mailer\Messenger\SendEmailMessage">
                <framework:sender service="async"/>
            </framework:routing>
        </framework:messenger>
    </framework:config>
</container>

// config/packages/messenger.php
$container->loadFromExtension('framework', [
    'messenger' => [
        'routing' => [
            'Symfony\Component\Mailer\Messenger\SendEmailMessage' => 'async',
        ],
    ],
]);

Thanks to this, instead of being delivered immediately, messages will be sent to the transport to be handled later (see messenger-worker).

Development & Debugging

Disabling Delivery

While developing (or testing), you may want to disable delivery of messages entirely. You can do this by forcing Mailer to use the NullTransport in only the dev environment:

# config/packages/dev/mailer.yaml
framework:
    mailer:
        dsn: 'smtp://null'

Note

If you're using Messenger and routing to a transport, the message will still be sent to that transport.

Always Send to the Same Address

Instead of disabling delivery entirely, you might want to always send emails to a specific address, instead of the real address. To do that, you can take advantage of the EnvelopeListener and register it only for the dev environment:

# config/services_dev.yaml
services:
    mailer.dev.set_recipients:
        class: Symfony\Component\Mailer\EventListener\EnvelopeListener
        tags: ['kernel.event_subscriber']
        arguments:
            $sender: null
            $recipients: ['youremail@example.com']