Sending Emails with Mailer
Warning: You are browsing the documentation for Symfony 6.2, which is no longer maintained.
Read the updated version of this page for Symfony 7.2 (the current stable version).
Sending Emails with Mailer
Installation
Symfony's Mailer & 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:
1
$ composer require symfony/mailer
Transport Setup
Emails are delivered via a "transport". Out of the box, you can deliver emails
over SMTP by configuring the DSN in your .env
file (the user
,
pass
and port
parameters are optional):
1 2
# .env
MAILER_DSN=smtp://user:pass@smtp.example.com:port
1 2 3 4
# config/packages/mailer.yaml
framework:
mailer:
dsn: '%env(MAILER_DSN)%'
Caution
If the username, password or host contain any character considered special in a
URI (such as +
, @
, $
, #
, /
, :
, *
, !
), you must
encode them. See RFC 3986 for the full list of reserved characters or use the
urlencode function to encode them.
Using Built-in Transports
DSN protocol | Example | Description |
---|---|---|
smtp | smtp://user:pass@smtp.example.com:25 |
Mailer uses an SMTP server to send emails |
sendmail | sendmail://default |
Mailer uses the local sendmail binary to send emails |
native | native://default |
Mailer uses the sendmail binary and options configured
in the sendmail_path setting of php.ini . On Windows
hosts, Mailer fallbacks to smtp and smtp_port
php.ini settings when sendmail_path is not configured. |
Caution
When using native://default
, if php.ini
uses the sendmail -t
command, you won't have error reporting and Bcc
headers won't be removed.
It's highly recommended to NOT use native://default
as you cannot control
how sendmail is configured (prefer using sendmail://default
if possible).
Using a 3rd Party Transport
Instead of using your own SMTP server or sendmail binary, you can send emails via a third-party provider:
Service | Install with |
---|---|
Amazon SES | composer require symfony/amazon-mailer |
Infobip | composer require symfony/infobip-mailer |
Mailchimp Mandrill | composer require symfony/mailchimp-mailer |
Mailgun | composer require symfony/mailgun-mailer |
Mailjet | composer require symfony/mailjet-mailer |
MailPace | composer require symfony/mail-pace-mailer |
Postmark | composer require symfony/postmark-mailer |
SendGrid | composer require symfony/sendgrid-mailer |
Sendinblue | composer require symfony/sendinblue-mailer |
6.2
The Infobip integration was introduced in Symfony 6.2 and the MailPace
integration was renamed in Symfony 6.2 (in previous Symfony versions it was
called OhMySMTP
).
Note
As a convenience, Symfony also provides support for Gmail (composer
require symfony/google-mailer
), but this should not be used in
production. In development, you should probably use an email catcher instead. Note that most supported providers also offer a
free tier.
Each library includes a Symfony Flex recipe that will add
a configuration example to your .env
file. For example, suppose you want to
use SendGrid. First, install it:
1
$ composer require symfony/sendgrid-mailer
You'll now have a new line in your .env
file that you can uncomment:
1 2
# .env
MAILER_DSN=sendgrid://KEY@default
The MAILER_DSN
isn't a real address: it's a convenient format that
offloads most of the configuration work to mailer. The sendgrid
scheme
activates the SendGrid provider that you just installed, which knows all about
how to deliver messages via SendGrid. The only part you need to change is the
KEY
placeholder.
Each provider has different environment variables that the Mailer uses to
configure the actual protocol, address and authentication for delivery. Some
also have options that can be configured with query parameters at the end of the
MAILER_DSN
- like ?region=
for Amazon SES or Mailgun. Some providers support
sending via http
, api
or smtp
. Symfony chooses the best available
transport, but you can force to use one:
1 2 3
# .env
# force to use SMTP instead of HTTP (which is the default)
MAILER_DSN=sendgrid+smtp://$SENDGRID_KEY@default
This table shows the full list of available DSN formats for each third party provider:
Provider | Formats |
---|---|
Amazon SES | |
Google Gmail |
|
Infobip |
|
Mailchimp Mandrill | |
Mailgun | |
Mailjet | |
MailPace |
|
Postmark |
|
Sendgrid |
|
Sendinblue |
|
Caution
If your credentials contain special characters, you must URL-encode them.
For example, the DSN ses+smtp://ABC1234:abc+12/345@default
should be
configured as ses+smtp://ABC1234:abc%2B12%2F345@default
Caution
If you want to use the ses+smtp
transport together with Messenger
to send messages in background,
you need to add the ping_threshold
parameter to your MAILER_DSN
with
a value lower than 10
: ses+smtp://USERNAME:PASSWORD@default?ping_threshold=9
Note
When using SMTP, the default timeout for sending a message before throwing an exception is the value defined in the default_socket_timeout PHP.ini option.
Note
Besides SMTP, many 3rd party transports offer a web API to send emails.
To do so, you have to install (additionally to the bridge)
the HttpClient component via composer require symfony/http-client
.
Note
To use Google Gmail, you must have a Google Account with 2-Step-Verification (2FA)
enabled and you must use App Password to authenticate. Also note that Google
revokes your App Passwords when you change your Google Account password and then
you need to generate a new one.
Using other methods (like XOAUTH2
or the Gmail API
) are not supported currently.
You should use Gmail for testing purposes only and use a real provider in production.
Tip
If you want to override the default host for a provider (to debug an issue using
a service like requestbin.com
), change default
by your host:
1 2
# .env
MAILER_DSN=mailgun+https://KEY:DOMAIN@requestbin.com
Note that the protocol is always HTTPs and cannot be changed.
Note
The specific transports, e.g. mailgun+smtp
are designed to work without any manual configuration.
Changing the port by appending it to your DSN is not supported for any of these <provider>+smtp` transports.
If you need to change the port, use the
smtp`` transport instead, like so:
1 2
# .env
MAILER_DSN=smtp://KEY:DOMAIN@smtp.eu.mailgun.org.com:25
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:
1
MAILER_DSN="failover(postmark+api://ID@default sendgrid+smtp://KEY@default)"
The failover-transport starts 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).
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:
1
MAILER_DSN="roundrobin(postmark+api://ID@default sendgrid+smtp://KEY@default)"
The round-robin transport starts with a randomly selected transport and then switches to the next available transport for each subsequent email.
As with the failover transport, round-robin retries deliveries until a transport succeeds (or all fail). In contrast to the failover transport, it spreads the load across all its transports.
TLS Peer Verification
By default, SMTP transports perform TLS peer verification. This behavior is
configurable with the verify_peer
option. Although it's not recommended to
disable this verification for security reasons, it can be useful while developing
the application or when using a self-signed certificate:
1
$dsn = 'smtp://user:pass@smtp.example.com?verify_peer=0';
Other Options
command
-
Command to be executed by
sendmail
transport:1
$dsn = 'sendmail://default?command=/usr/sbin/sendmail%20-oi%20-t'
local_domain
-
The domain name to use in
HELO
command:1
$dsn = 'smtps://smtp.example.com?local_domain=example.org'
restart_threshold
-
The maximum number of messages to send before re-starting the transport. It can be used together with
restart_threshold_sleep
:1
$dsn = 'smtps://smtp.example.com?restart_threshold=10&restart_threshold_sleep=1'
restart_threshold_sleep
-
The number of seconds to sleep between stopping and re-starting the transport. It's common to combine it with
restart_threshold
:1
$dsn = 'smtps://smtp.example.com?restart_threshold=10&restart_threshold_sleep=1'
ping_threshold
-
The minimum number of seconds between two messages required to ping the server:
1
$dsn = 'smtps://smtp.example.com?ping_threshold=200'
max_per_second
-
The number of messages to send per second (0 to disable this limitation):
1
$dsn = 'smtps://smtp.example.com?max_per_second=2'
6.2
The
max_per_second
option was introduced in Symfony 6.2.
Creating & Sending Messages
To send an email, get a Mailer instance by type-hinting MailerInterface and create an Email object:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
// src/Controller/MailerController.php
namespace App\Controller;
use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\Mailer\MailerInterface;
use Symfony\Component\Mime\Email;
use Symfony\Component\Routing\Annotation\Route;
class MailerController extends AbstractController
{
#[Route('/email')]
public function sendEmail(MailerInterface $mailer): Response
{
$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 the transport you configured. If the transport is configured to send emails asynchronously, the message won't be actually sent until a worker consumes it.
Email Addresses
All the methods that require email addresses (from()
, to()
, etc.) accept
both strings or address objects:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
// ...
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::create('Fabien Potencier <fabien@example.com>'))
// ...
;
Tip
Instead of calling ->from()
every time you create a new email, you can
configure emails globally to set the
same From
email to all messages.
Note
The local part of the address (what goes before the @
) can include UTF-8
characters, except for the sender address (to avoid issues with bounced emails).
For example: föóbàr@example.com
, 用户@example.com
, θσερ@example.com
, etc.
Use addTo()
, addCc()
, or addBcc()
methods to add more addresses:
1 2 3 4 5 6 7 8
$email = (new Email())
->to('foo@example.com')
->addTo('bar@example.com')
->cc('cc@example.com')
->addCc('cc2@example.com')
// ...
;
Alternatively, you can pass multiple addresses to each method:
1 2 3 4 5 6 7 8
$toAddresses = ['foo@example.com', new Address('bar@example.com')];
$email = (new Email())
->to(...$toAddresses)
->cc('cc1@example.com', 'cc2@example.com')
// ...
;
Message Headers
Messages include a number of header fields to describe their contents. Symfony sets all the required headers automatically, but you can set your own headers too. There are different types of headers (Id header, Mailbox header, Date header, etc.) but most of the times you'll set text headers:
1 2 3 4 5 6 7 8 9 10 11 12
$email = (new Email())
->getHeaders()
// this non-standard header tells compliant autoresponders ("email holiday mode") to not
// reply to this message because it's an automated email
->addTextHeader('X-Auto-Response-Suppress', 'OOF, DR, RN, NRN, AutoReply')
// use an array if you want to add a header with multiple values
// (for example in the "References" or "In-Reply-To" header)
->addIdHeader('References', ['123@example.com', '456@example.com'])
// ...
;
Tip
Instead of calling ->addTextHeader()
every time you create a new email, you can
configure emails globally to set the same
headers to all sent emails.
Message Contents
The text and HTML contents of the email messages can be strings (usually the result of rendering some template) or PHP resources:
1 2 3 4 5 6 7 8 9 10
$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 addPart()
method with a BodyFile
to add files that exist on your file system:
1 2 3 4 5 6 7 8 9 10 11 12
use Symfony\Component\Mime\Part\DataPart;
use Symfony\Component\Mime\Part\File;
// ...
$email = (new Email())
// ...
->addPart(new DataPart(new File('/path/to/documents/terms-of-use.pdf')))
// optionally you can tell email clients to display a custom name for the file
->addPart(new DataPart(new File('/path/to/documents/privacy.pdf'), 'Privacy Policy'))
// optionally you can provide an explicit MIME type (otherwise it's guessed)
->addPart(new DataPart(new File('/path/to/documents/contract.doc'), 'Contract', 'application/msword'))
;
Alternatively you can attach contents from a stream by passing it directly to the DataPart
:
1 2 3 4
$email = (new Email())
// ...
->addPart(new DataPart(fopen('/path/to/documents/contract.doc', 'r')))
;
6.2
In Symfony versions previous to 6.2, the methods attachFromPath()
and
attach()
could be used to add attachments. These methods have been
deprecated and replaced with addPart()
.
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 addPart()
method to add an image from a
file or stream:
1 2 3 4 5 6 7
$email = (new Email())
// ...
// get the image contents from a PHP resource
->addPart((new DataPart(fopen('/path/to/images/logo.png', 'r'), 'logo', 'image/png'))->asInline())
// get the image contents from an existing file
->addPart((new DataPart(new File('/path/to/images/signature.gif'), 'footer-signature', 'image/gif'))->asInline())
;
Use the asInline()
method to embed the content instead of attaching it.
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:
1 2 3 4 5 6 7 8 9 10 11
$email = (new Email())
// ...
->addPart((new DataPart(fopen('/path/to/images/logo.png', 'r'), 'logo', 'image/png'))->asInline())
->addPart((new DataPart(new File('/path/to/images/signature.gif'), 'footer-signature', 'image/gif'))->asInline())
// reference images using the syntax 'cid:' + "image embed name"
->html('<img src="cid:logo"> ... <img src="cid:footer-signature"> ...')
// use the same syntax for images included as HTML background images
->html('... <div background="cid:footer-signature"> ... </div> ...')
;
6.1
The support of embedded images as HTML backgrounds was introduced in Symfony 6.1.
6.2
In Symfony versions previous to 6.2, the methods embedFromPath()
and
embed()
could be used to embed images. These methods have been deprecated
and replaced with addPart()
together with inline DataPart
objects.
Configuring Emails Globally
Instead of calling ->from()
on each Email you create, you can configure this
value globally so that it is set on all sent emails. The same is true with ->to()
and headers.
1 2 3 4 5 6 7 8 9 10
# config/packages/mailer.yaml
framework:
mailer:
envelope:
sender: 'fabien@example.com'
recipients: ['foo@example.com', 'bar@example.com']
headers:
From: 'Fabien <fabien@example.com>'
Bcc: 'baz@example.com'
X-Custom-Header: 'foobar'
Caution
Some third-party providers don't support the usage of keywords like from
in the headers
. Check out your provider's documentation before setting
any global header.
Handling Sending Failures
Symfony Mailer considers that sending was successful when your transport (SMTP server or third-party provider) accepts the mail for further delivery. The message can later be lost or not delivered because of some problem in your provider, but that's out of reach for your Symfony application.
If there's an error when handing over the email to your transport, Symfony throws a TransportExceptionInterface. Catch that exception to recover from the error or to display some message:
1 2 3 4 5 6 7 8 9 10
use Symfony\Component\Mailer\Exception\TransportExceptionInterface;
$email = new Email();
// ...
try {
$mailer->send($email);
} catch (TransportExceptionInterface $e) {
// some error prevented the email sending; display an
// error message or try to resend the message
}
Debugging Emails
The SentMessage object returned by the
send()
method of the TransportInterface
provides access to the original message (getOriginalMessage()
) and to some
debug information (getDebug()
) such as the HTTP calls done by the HTTP
transports, which is useful to debug errors.
Note
If your code used MailerInterface, you
need to replace it by TransportInterface
to have the SentMessage
object returned.
Note
Some mailer providers change the Message-Id
when sending the email. The
getMessageId()
method from SentMessage
always returns the definitive
ID of the message (being the original random ID generated by Symfony or the
new ID generated by the mailer provider).
The exceptions related to mailer transports (those which implement
TransportException) also provide
this debug information via the getDebug()
method.
Twig: HTML & CSS
The Mime component integrates with the Twig template engine 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:
1 2 3 4
$ composer require symfony/twig-bundle
# or if you're using the component in a non-Symfony app:
# composer require symfony/twig-bridge
HTML Content
To define the contents of your email with Twig, use the TemplatedEmail class. This class extends the normal Email class but adds some new methods for Twig templates:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
use Symfony\Bridge\Twig\Mime\TemplatedEmail;
$email = (new TemplatedEmail())
->from('fabien@example.com')
->to(new Address('ryan@example.com'))
->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:
1 2 3 4 5 6 7 8 9 10 11 12
{# 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
WrappedTemplatedEmail.
Text Content
When the text content of a TemplatedEmail
is not explicitly defined, it is
automatically generated from the HTML contents.
Symfony uses the following strategy when generating the text version of an email:
- If an explicit HTML to text converter has been configured (see twig.mailer.html_to_text_converter), it calls it;
- If not, and if you have league/html-to-markdown installed in your application, it uses it 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:
1 2 3 4 5 6 7 8 9
+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:
1 2 3 4 5 6 7
# 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:
1 2 3 4 5
{# '@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:
1
$ composer require twig/extra-bundle twig/cssinliner-extra
The extension is enabled automatically. To use it, wrap the entire template
with the inline_css
filter:
1 2 3 4 5 6 7 8 9 10 11
{% 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:
1 2 3 4
{% apply inline_css(source('@styles/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 styles
that points to the directory where email.css
lives:
1 2 3 4 5 6 7
# config/packages/twig.yaml
twig:
# ...
paths:
# point this wherever your css files live
'%kernel.project_dir%/assets/styles': styles
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):
1 2
# instead of league/commonmark, you can also use erusev/parsedown or michelf/php-markdown
$ composer require twig/extra-bundle twig/markdown-extra league/commonmark
The extension adds a markdown_to_html
filter, which you can use to convert parts or
the entire email contents from Markdown to HTML:
1 2 3 4 5 6 7 8 9
{% apply markdown_to_html %}
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 HTML-like tags which are later transformed into the real HTML code sent to users:
1 2 3 4 5 6
<!-- 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:
1
$ composer require twig/extra-bundle twig/inky-extra
The extension adds an inky_to_html
filter, which can be used to convert
parts or the entire email contents from Inky to HTML:
1 2 3 4 5 6 7 8 9 10 11 12
{% apply inky_to_html %}
<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:
1 2 3
{% apply inky_to_html|inline_css(source('@styles/foundation-emails.css')) %}
{# ... #}
{% endapply %}
This makes use of the styles Twig namespace we created
earlier. You could, for example, download the foundation-emails.css file
directly from GitHub and save it in assets/styles
.
Signing and Encrypting Messages
It's possible to sign and/or encrypt email messages 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 S/MIME security certificate.
Tip
When using OpenSSL to generate certificates, make sure to add the
-addtrust emailProtection
command option.
Caution
Signing and encrypting messages require their contents to be fully rendered. For example, the content of templated emails is rendered by a MessageListener. So, if you want to sign and/or encrypt such a message, you need to do it in a MessageEvent listener run after it (you need to set a negative priority to your listener).
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.
You can sign messages using either S/MIME
or DKIM
. In both cases, 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.
Caution
If you use message signature, sending to Bcc
will be removed from the
message. If you need to send a message to multiple recipients, you need
to compute a new signature for each recipient.
S/MIME Signer
S/MIME is a standard for public key encryption and signing of MIME data. It requires using both a certificate and a private key:
1 2 3 4 5 6 7 8 9 10 11 12 13 14
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
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.
DKIM Signer
DKIM is an email authentication method that affixes a digital signature, linked to a domain name, to each outgoing email messages. It requires a private key but not a certificate:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
use Symfony\Component\Mime\Crypto\DkimSigner;
use Symfony\Component\Mime\Email;
$email = (new Email())
->from('hello@example.com')
// ...
->html('...');
// first argument: same as openssl_pkey_get_private(), either a string with the
// contents of the private key or the absolute path to it (prefixed with 'file://')
// second and third arguments: the domain name and "selector" used to perform a DNS lookup
// (the selector is a string used to point to a specific DKIM public key record in your DNS)
$signer = new DkimSigner('file:///path/to/private-key.key', 'example.com', 'sf');
// if the private key has a passphrase, pass it as the fifth argument
// new DkimSigner('file:///path/to/private-key.key', 'example.com', 'sf', [], 'the-passphrase');
$signedEmail = $signer->sign($email);
// now use the Mailer component to send this $signedEmail instead of the original email
// DKIM signer provides many config options and a helper object to configure them
use Symfony\Component\Mime\Crypto\DkimOptions;
$signedEmail = $signer->sign($email, (new DkimOptions())
->bodyCanon('relaxed')
->headerCanon('relaxed')
->headersToIgnore(['Message-ID'])
->toArray()
);
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:
1 2 3 4 5 6 7 8 9 10 11
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:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
$firstEmail = (new Email())
// ...
->to('jane@example.com');
$secondEmail = (new Email())
// ...
->to('john@example.com');
// the second optional argument of SMimeEncrypter defines which encryption algorithm is used
// (it must be one of these constants: https://www.php.net/manual/en/openssl.ciphers.php)
$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);
Multiple Email Transports
You may want to use more than one mailer transport for delivery of your messages.
This can be configured by replacing the dsn
configuration entry with a
transports
entry, like:
1 2 3 4 5 6
# config/packages/mailer.yaml
framework:
mailer:
transports:
main: '%env(MAILER_DSN)%'
alternative: '%env(MAILER_DSN_IMPORTANT)%'
By default the first transport is used. The other transports can be selected by
adding an X-Transport
header (which Mailer will remove automatically from
the final email):
1 2 3 4 5 6
// Send using first transport ("main"):
$mailer->send($email);
// ... or use the transport "alternative":
$email->getHeaders()->addTextHeader('X-Transport', 'alternative');
$mailer->send($email);
Sending Messages Async
When you call $mailer->send($email)
, the email is sent to the transport immediately.
To improve performance, you can leverage Messenger to send
the messages later via a Messenger transport.
Start by following the Messenger documentation and configuring
a transport. Once everything is set up, when you call $mailer->send()
, a
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:
1 2 3 4 5 6 7 8
# config/packages/messenger.yaml
framework:
messenger:
transports:
async: "%env(MESSENGER_TRANSPORT_DSN)%"
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: Sync & Queued Message Handling). Note that the "rendering" of the email (computed headers, body rendering, ...) is also deferred and will only happen just before the email is sent by the Messenger handler.
6.2
The following example about rendering the email before calling
$mailer->send($email)
works as of Symfony 6.2.
When sending an email asynchronously, its instance must be serializable.
This is always the case for Email
instances, but when sending a
TemplatedEmail, you must ensure that
the context
is serializable. If you have non-serializable variables,
like Doctrine entities, either replace them with more specific variables or
render the email before calling $mailer->send($email)
:
1 2 3 4 5 6 7 8 9 10 11 12 13
use Symfony\Component\Mailer\MailerInterface;
use Symfony\Component\Mime\BodyRendererInterface;
public function action(MailerInterface $mailer, BodyRendererInterface $bodyRenderer): void
{
$email = (new TemplatedEmail())
->htmlTemplate($template)
->context($context)
;
$bodyRenderer->render($email);
$mailer->send($email);
}
You can configure which bus is used to dispatch the message using the message_bus
option.
You can also set this to false
to call the Mailer transport directly and
disable asynchronous delivery.
1 2 3 4
# config/packages/mailer.yaml
framework:
mailer:
message_bus: app.another_bus
Note
In cases of long-running scripts, and when Mailer uses the
SmtpTransport
you may manually disconnect from the SMTP server to avoid keeping
an open connection to the SMTP server in between sending emails.
You can do so by using the stop()
method.
6.1
The stop() method was made public in Symfony 6.1.
You can also select the transport by adding an X-Bus-Transport
header (which
will be remove automatically from the final message):
1 2 3
// Use the bus transport "app.another_bus":
$email->getHeaders()->addTextHeader('X-Bus-Transport', 'app.another_bus');
$mailer->send($email);
6.2
The X-Bus-Transport
header support was introduced in Symfony 6.2.
Adding Tags and Metadata to Emails
Certain 3rd party transports support email tags and metadata, which can be used for grouping, tracking and workflows. You can add those by using the TagHeader and MetadataHeader classes. If your transport supports headers, it will convert them to their appropriate format:
1 2 3 4 5 6
use Symfony\Component\Mailer\Header\MetadataHeader;
use Symfony\Component\Mailer\Header\TagHeader;
$email->getHeaders()->add(new TagHeader('password-reset'));
$email->getHeaders()->add(new MetadataHeader('Color', 'blue'));
$email->getHeaders()->add(new MetadataHeader('Client-ID', '12345'));
If your transport does not support tags and metadata, they will be added as custom headers:
1 2 3
X-Tag: password-reset
X-Metadata-Color: blue
X-Metadata-Client-ID: 12345
The following transports currently support tags and metadata:
- Mailchimp
- Mailgun
- Postmark
- Sendgrid
- Sendinblue
The following transports only support tags:
- MailPace
The following transports only support metadata:
- Amazon SES (note that Amazon refers to this feature as "tags", but Symfony calls it "metadata" because it contains a key and a value)
6.1
Metadata support for Amazon SES was introduced in Symfony 6.1.
Draft Emails
6.1
Symfony\Component\Mime\DraftEmail
was introduced in 6.1.
DraftEmail is a special instance of
Email. Its purpose is to build up an email
(with body, attachments, etc) and make available to download as an .eml
with
the X-Unsent
header. Many email clients can open these files and interpret
them as draft emails. You can use these to create advanced mailto:
links.
Here's an example of making one available to download:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
// src/Controller/DownloadEmailController.php
namespace App\Controller;
use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpFoundation\ResponseHeaderBag;
use Symfony\Component\Mime\DraftEmail;
use Symfony\Component\Routing\Annotation\Route;
class DownloadEmailController extends AbstractController
{
#[Route('/download-email')]
public function __invoke(): Response
{
$message = (new DraftEmail())
->html($this->renderView(/* ... */))
->attach(/* ... */)
;
$response = new Response($message->toString());
$contentDisposition = $response->headers->makeDisposition(
ResponseHeaderBag::DISPOSITION_ATTACHMENT,
'download.eml'
);
$response->headers->set('Content-Type', 'message/rfc822');
$response->headers->set('Content-Disposition', $contentDisposition);
return $response;
}
}
Note
As it's possible for DraftEmail's to be created without a To/From they cannot be sent with the mailer.
Mailer Events
MessageEvent
Event Class: MessageEvent
MessageEvent
allows to change the Mailer message and the envelope before
the email is sent:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
use Symfony\Component\EventDispatcher\EventSubscriberInterface;
use Symfony\Component\Mailer\Event\MessageEvent;
use Symfony\Component\Mime\Email;
public function onMessage(MessageEvent $event): void
{
$message = $event->getMessage();
if (!$message instanceof Email) {
return;
}
// do something with the message (logging, ...)
// and/or add some Messenger stamps
$event->addStamp(new SomeMessengerStamp());
}
6.2
Methods addStamp()
and getStamps()
were introduced in Symfony 6.2.
Execute this command to find out which listeners are registered for this event and their priorities:
1
$ php bin/console debug:event-dispatcher "Symfony\Component\Mailer\Event\MessageEvent"
SentMessageEvent
Event Class: SentMessageEvent
6.2
The SentMessageEvent
event was introduced in Symfony 6.2.
SentMessageEvent
allows you to act on the SentMessage
class to access the original message (getOriginalMessage()
) and some debugging
information (getDebug()
) such as the HTTP calls made by the HTTP transports,
which is useful for debugging errors:
1 2 3 4 5 6 7 8 9 10 11 12 13
use Symfony\Component\EventDispatcher\EventSubscriberInterface;
use Symfony\Component\Mailer\Event\SentMessageEvent;
use Symfony\Component\Mailer\SentMessage;
public function onMessage(SentMessageEvent $event): void
{
$message = $event->getMessage();
if (!$message instanceof SentMessage) {
return;
}
// do something with the message
}
Execute this command to find out which listeners are registered for this event and their priorities:
1
$ php bin/console debug:event-dispatcher "Symfony\Component\Mailer\Event\SentMessageEvent"
FailedMessageEvent
Event Class: FailedMessageEvent
6.2
The FailedMessageEvent
event was introduced in Symfony 6.2.
FailedMessageEvent
allows acting on the the initial message in case of a failure:
1 2 3 4 5 6 7 8 9 10
use Symfony\Component\EventDispatcher\EventSubscriberInterface;
use Symfony\Component\Mailer\Event\FailedMessageEvent;
public function onMessage(FailedMessageEvent $event): void
{
// e.g you can get more information on this error when sending an email
$event->getError();
// do something with the message
}
Execute this command to find out which listeners are registered for this event and their priorities:
1
$ php bin/console debug:event-dispatcher "Symfony\Component\Mailer\Event\FailedMessageEvent"
Development & Debugging
Enabling an Email Catcher
When developing locally, it is recommended to use an email catcher. If you have enabled Docker support via Symfony recipes, an email catcher is automatically configured. In addition, if you are using the Symfony local web server, the mailer DSN is automatically exposed via the symfony binary Docker integration.
Sending Test Emails
Symfony provides a command to send emails, which is useful during development to test if sending emails works correctly:
1 2 3
# the only mandatory argument is the recipient address
# (check the command help to learn about its options)
$ php bin/console mailer:test someone@example.com
This command bypasses the Messenger bus, if configured, to ease testing emails even when the Messenger consumer is not running.
6.2
The mailer:test
command was introduced in Symfony 6.2.
Disabling Delivery
While developing (or testing), you may want to disable delivery of messages
entirely. You can do this by using null://null
as the mailer DSN, either in
your .env configuration files or in
the mailer configuration file (e.g. in the dev
or test
environments):
1 2 3 4 5
# config/packages/mailer.yaml
when@dev:
framework:
mailer:
dsn: 'null://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:
1 2 3 4 5 6
# config/packages/mailer.yaml
when@dev:
framework:
mailer:
envelope:
recipients: ['youremail@example.com']
Write a Functional Test
Symfony provides lots of built-in mailer assertions to functionally test that an email was sent, its contents or headers, etc. They are available in test classes extending KernelTestCase or when using the MailerAssertionsTrait:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
// tests/Controller/MailControllerTest.php
namespace App\Tests\Controller;
use Symfony\Bundle\FrameworkBundle\Test\WebTestCase;
class MailControllerTest extends WebTestCase
{
public function testMailIsSentAndContentIsOk(): void
{
$client = static::createClient();
$client->request('GET', '/mail/send');
$this->assertResponseIsSuccessful();
$this->assertEmailCount(1); // use assertQueuedEmailCount() when using Messenger
$email = $this->getMailerMessage();
$this->assertEmailHtmlBodyContains($email, 'Welcome');
$this->assertEmailTextBodyContains($email, 'Welcome');
}
}