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You are browsing the Symfony 4.4 documentation, which changes significantly from Symfony 3.x. If your app doesn't use Symfony 4.4 yet, browse the Symfony 3.4 documentation.

The Mailer Component

The Mailer Component

The Mailer component helps sending emails.

If you're using the Symfony Framework, read the Symfony Framework Mailer documentation.

New in version 4.3: The Mailer component was introduced in Symfony 4.3.

Installation

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$ composer require symfony/mailer

Note

If you install this component outside of a Symfony application, you must require the vendor/autoload.php file in your code to enable the class autoloading mechanism provided by Composer. Read this article for more details.

Usage

The Mailer component has two main classes: a Transport and the Mailer itself:

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use Symfony\Component\Mailer\Mailer;
use Symfony\Component\Mailer\Transport\Smtp\SmtpTransport;

$transport = new SmtpTransport('localhost');
$mailer = new Mailer($transport);
$mailer->send($email);

The $email object is created via the Mime component.

Transport

The only transport that comes pre-installed is SMTP.

Below is the list of other popular providers with built-in support:

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

For example, suppose you want to use Google's Gmail SMTP server. First, install it:

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$ composer require symfony/google-mailer

Then, use the SMTP Gmail transport:

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use Symfony\Component\Mailer\Bridge\Google\Smtp\GmailTransport;

$transport = new GmailTransport('user', 'pass');
$mailer = new Mailer($transport);
$mailer->send($email);

Each provider provides up to 3 transports: standard SMTP, HTTP (it uses the provider's API but the body is created by the mailer component), API (it uses the full API of the provider with no control over the body creation -- features might be limited as well).

The mailer component provides a convenient way to create a transport from a DSN:

use Symfony\Component\Mailer\Transport;

$transport = Transport::fromDsn($dsn);

Where $dsn depends on the provider you want to use. For plain SMTP, use smtp://user:pass@example.com or smtp://sendmail to use the sendmail binary. For third-party providers, refers to the following table:

Provider SMTP HTTP API
Amazon SES smtp://ACCESS_KEY:SECRET_KEY@ses http://ACCESS_KEY:SECRET_KEY@ses api://ACCESS_KEY:SECRET_KEY@ses
Google Gmail smtp://USERNAME:PASSWORD@gmail n/a n/a
Mailchimp Mandrill smtp://USERNAME:PASSWORD@mandrill http://KEY@mandrill api://KEY@mandrill
Mailgun smtp://USERNAME:PASSWORD@mailgun http://KEY:DOMAIN@mailgun api://KEY:DOMAIN@mailgun
Postmark smtp://ID:ID@postmark n/a api://KEY@postmark
Sendgrid smtp://apikey:KEY@sendgrid n/a api://KEY@sendgrid

High Availability

Symfony's mailer supports high availability via a technique called "failover" to ensure that emails are sent even if one mailer server fails .

A failover transport is configured with two or more transports and the failover keyword:

$dsn = 'failover(api://[email protected] smtp://[email protected])';

The mailer will start using the first transport. If the sending fails, the mailer won't retry it with the other transports, but it will switch to the next transport automatically for the following deliveries.

Load Balancing

Symfony's mailer supports load balancing via a technique called "round-robin" to distribute the mailing workload across multiple transports .

A round-robin transport is configured with two or more transports and the roundrobin keyword:

$dsn = 'roundrobin(api://[email protected] smtp://[email protected])'

The mailer will start using the first transport and if it fails, it will retry the same delivery with the next transports until one of them succeeds (or until all of them fail).

Sending emails asynchronously

If you want to send emails asynchronously, install the Messenger component.

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$ composer require symfony/messenger

Then, instantiate and pass a MessageBus as a second argument to Mailer:

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use Symfony\Component\Mailer\Envelope;
use Symfony\Component\Mailer\Mailer;
use Symfony\Component\Mailer\Messenger\MessageHandler;
use Symfony\Component\Mailer\Messenger\SendEmailMessage;
use Symfony\Component\Mailer\Transport;
use Symfony\Component\Messenger\Handler\HandlersLocator;
use Symfony\Component\Messenger\MessageBus;
use Symfony\Component\Messenger\Middleware\HandleMessageMiddleware;
use Symfony\Component\Mime\Address;

$dsn = 'change-dsn-accordingly';

$transport = Transport::fromDsn($dsn);
$handler = new MessageHandler($transport);

$bus = new MessageBus([
    new HandleMessageMiddleware(new HandlersLocator([
        SendEmailMessage::class => [$handler],
    ])),
]);

$mailer = new Mailer($transport, $bus);
$mailer->send($email);

// you can pass an optional Envelope
$mailer->send($email, new Envelope(
    new Address('[email protected]'),
    [
        new Address('[email protected]'),
    ]
));

Learn More

To learn more about how to use the mailer component, refer to the Symfony Framework Mailer documentation.

This work, including the code samples, is licensed under a Creative Commons BY-SA 3.0 license.