Migrate to Symfony Mailer

Signed-off-by: Côme Chilliet <come.chilliet@nextcloud.com>

4 files changed, 225 insertions, 173 deletions

diff --git a/lib/private/Mail/Attachment.php b/lib/private/Mail/Attachment.php
index 12f71df86d9..5bfe0dd0522 100644
--- a/lib/private/Mail/Attachment.php
+++ b/lib/private/Mail/Attachment.php
@@ -27,6 +27,7 @@ declare(strict_types=1);
 namespace OC\Mail;
 
 use OCP\Mail\IAttachment;
+use Symfony\Component\Mime\Email;
 
 /**
  * Class Attachment
@@ -35,11 +36,21 @@ use OCP\Mail\IAttachment;
  * @since 13.0.0
  */
 class Attachment implements IAttachment {
-	/** @var \Swift_Mime_Attachment */
-	protected $swiftAttachment;
+	private ?string $body;
+	private ?string $name;
+	private ?string $contentType;
+	private ?string $path;
 
-	public function __construct(\Swift_Mime_Attachment $attachment) {
-		$this->swiftAttachment = $attachment;
+	public function __construct(
+		?string $body,
+		?string $name,
+		?string $contentType,
+		?string $path = null
+	) {
+		$this->body = $body;
+		$this->name = $name;
+		$this->contentType = $contentType;
+		$this->path = $path;
 	}
 
 	/**
@@ -48,7 +59,7 @@ class Attachment implements IAttachment {
 	 * @since 13.0.0
 	 */
 	public function setFilename(string $filename): IAttachment {
-		$this->swiftAttachment->setFilename($filename);
+		$this->name = $filename;
 		return $this;
 	}
 
@@ -58,7 +69,7 @@ class Attachment implements IAttachment {
 	 * @since 13.0.0
 	 */
 	public function setContentType(string $contentType): IAttachment {
-		$this->swiftAttachment->setContentType($contentType);
+		$this->contentType = $contentType;
 		return $this;
 	}
 
@@ -68,14 +79,15 @@ class Attachment implements IAttachment {
 	 * @since 13.0.0
 	 */
 	public function setBody(string $body): IAttachment {
-		$this->swiftAttachment->setBody($body);
+		$this->body = $body;
 		return $this;
 	}
 
-	/**
-	 * @return \Swift_Mime_Attachment
-	 */
-	public function getSwiftAttachment(): \Swift_Mime_Attachment {
-		return $this->swiftAttachment;
+	public function attach(Email $symfonyEmail): void {
+		if ($this->path !== null) {
+			$symfonyEmail->attachFromPath($this->path, $this->name, $this->contentType);
+		} else {
+			$symfonyEmail->attach($this->body, $this->name, $this->contentType);
+		}
 	}
 }
diff --git a/lib/private/Mail/Mailer.php b/lib/private/Mail/Mailer.php
index d0c3b04eacb..05ef0bf5139 100644
--- a/lib/private/Mail/Mailer.php
+++ b/lib/private/Mail/Mailer.php
@@ -50,6 +50,15 @@ use OCP\Mail\IEMailTemplate;
 use OCP\Mail\IMailer;
 use OCP\Mail\IMessage;
 use Psr\Log\LoggerInterface;
+use Symfony\Component\Mailer\Exception\TransportExceptionInterface;
+use Symfony\Component\Mailer\Mailer as SymfonyMailer;
+use Symfony\Component\Mailer\MailerInterface;
+use Symfony\Component\Mailer\Transport\SendmailTransport;
+use Symfony\Component\Mailer\Transport\Smtp\EsmtpTransport;
+use Symfony\Component\Mailer\Transport\Smtp\Stream\SocketStream;
+use Symfony\Component\Mime\Email;
+use Symfony\Component\Mime\Exception\InvalidArgumentException;
+use Symfony\Component\Mime\Exception\RfcComplianceException;
 
 /**
  * Class Mailer provides some basic functions to create a mail message that can be used in combination with
@@ -70,12 +79,10 @@ use Psr\Log\LoggerInterface;
  * @package OC\Mail
  */
 class Mailer implements IMailer {
-	/** @var \Swift_Mailer Cached mailer */
-	private $instance = null;
+	private ?MailerInterface $instance = null;
 	private IConfig $config;
 	private LoggerInterface $logger;
-	/** @var Defaults */
-	private $defaults;
+	private Defaults $defaults;
 	private IURLGenerator $urlGenerator;
 	private IL10N $l10n;
 	private IEventDispatcher $dispatcher;
@@ -100,11 +107,11 @@ class Mailer implements IMailer {
 	/**
 	 * Creates a new message object that can be passed to send()
 	 *
-	 * @return IMessage
+	 * @return Message
 	 */
-	public function createMessage(): IMessage {
+	public function createMessage(): Message {
 		$plainTextOnly = $this->config->getSystemValue('mail_send_plaintext_only', false);
-		return new Message(new \Swift_Message(), $plainTextOnly);
+		return new Message(new Email(), $plainTextOnly);
 	}
 
 	/**
@@ -115,7 +122,7 @@ class Mailer implements IMailer {
 	 * @since 13.0.0
 	 */
 	public function createAttachment($data = null, $filename = null, $contentType = null): IAttachment {
-		return new Attachment(new \Swift_Attachment($data, $filename, $contentType));
+		return new Attachment($data, $filename, $contentType);
 	}
 
 	/**
@@ -125,7 +132,7 @@ class Mailer implements IMailer {
 	 * @since 13.0.0
 	 */
 	public function createAttachmentFromPath(string $path, $contentType = null): IAttachment {
-		return new Attachment(\Swift_Attachment::fromPath($path, $contentType));
+		return new Attachment(null, null, $contentType, $path);
 	}
 
 	/**
@@ -162,49 +169,82 @@ class Mailer implements IMailer {
 	 * Send the specified message. Also sets the from address to the value defined in config.php
 	 * if no-one has been passed.
 	 *
-	 * @param IMessage|Message $message Message to send
-	 * @return string[] Array with failed recipients. Be aware that this depends on the used mail backend and
-	 * therefore should be considered
-	 * @throws \Exception In case it was not possible to send the message. (for example if an invalid mail address
-	 * has been supplied.)
+	 * If sending failed, the recipients that failed will be returned (to, cc and bcc).
+	 * Will output additional debug info if 'mail_smtpdebug' => 'true' is set in config.php
+	 *
+	 * @param IMessage $message Message to send
+	 * @return string[] $failedRecipients
 	 */
 	public function send(IMessage $message): array {
 		$debugMode = $this->config->getSystemValue('mail_smtpdebug', false);
 
+		if (!($message instanceof Message)) {
+			throw new InvalidArgumentException('Object not of type ' . Message::class);
+		}
+
 		if (empty($message->getFrom())) {
 			$message->setFrom([\OCP\Util::getDefaultEmailAddress('no-reply') => $this->defaults->getName()]);
 		}
 
-		$failedRecipients = [];
-
 		$mailer = $this->getInstance();
 
-		// Enable logger if debug mode is enabled
-		if ($debugMode) {
-			$mailLogger = new \Swift_Plugins_Loggers_ArrayLogger();
-			$mailer->registerPlugin(new \Swift_Plugins_LoggerPlugin($mailLogger));
-		}
+		$this->dispatcher->dispatchTyped(new BeforeMessageSent($message));
 
+		try {
+			$message->setRecipients();
+		} catch (InvalidArgumentException|RfcComplianceException $e) {
+			$logMessage = sprintf(
+				'Could not send mail to "%s" with subject "%s" as validation for address failed',
+				print_r(array_merge($message->getTo(), $message->getCc(), $message->getBcc()), true),
+				$message->getSubject()
+			);
+			$this->logger->debug($logMessage, ['app' => 'core', 'exception' => $e]);
+			$recipients = array_merge($message->getTo(), $message->getCc(), $message->getBcc());
+			$failedRecipients = [];
+
+			array_walk($recipients, function ($value, $key) use (&$failedRecipients) {
+				if (is_numeric($key)) {
+					$failedRecipients[] = $value;
+				} else {
+					$failedRecipients[] = $key;
+				}
+			});
 
-		$this->dispatcher->dispatchTyped(new BeforeMessageSent($message));
+			return $failedRecipients;
+		}
 
-		$mailer->send($message->getSwiftMessage(), $failedRecipients);
+		try {
+			$mailer->send($message->getSymfonyEmail());
+		} catch (TransportExceptionInterface $e) {
+			$logMessage = sprintf('Sending mail to "%s" with subject "%s" failed', print_r($message->getTo(), true), $message->getSubject());
+			$this->logger->debug($logMessage, ['app' => 'core', 'exception' => $e]);
+			if ($debugMode) {
+				$this->logger->debug($e->getDebug(), ['app' => 'core']);
+			}
+			$recipients = array_merge($message->getTo(), $message->getCc(), $message->getBcc());
+			$failedRecipients = [];
+
+			array_walk($recipients, function ($value, $key) use (&$failedRecipients) {
+				if (is_numeric($key)) {
+					$failedRecipients[] = $value;
+				} else {
+					$failedRecipients[] = $key;
+				}
+			});
+
+			return $failedRecipients;
+		}
 
 		// Debugging logging
 		$logMessage = sprintf('Sent mail to "%s" with subject "%s"', print_r($message->getTo(), true), $message->getSubject());
-		if (!empty($failedRecipients)) {
-			$logMessage .= sprintf(' (failed for "%s")', print_r($failedRecipients, true));
-		}
 		$this->logger->debug($logMessage, ['app' => 'core']);
-		if ($debugMode && isset($mailLogger)) {
-			$this->logger->debug($mailLogger->dump(), ['app' => 'core']);
-		}
 
-		return $failedRecipients;
+		return [];
 	}
 
 	/**
-	 * Checks if an e-mail address is valid
+	 * @deprecated 26.0.0 Implicit validation is done in \OC\Mail\Message::setRecipients
+	 *                    via \Symfony\Component\Mime\Address::__construct
 	 *
 	 * @param string $email Email address to be validated
 	 * @return bool True if the mail address is valid, false otherwise
@@ -217,28 +257,10 @@ class Mailer implements IMailer {
 		$validator = new EmailValidator();
 		$validation = new RFCValidation();
 
-		return $validator->isValid($this->convertEmail($email), $validation);
+		return $validator->isValid($email, $validation);
 	}
 
-	/**
-	 * SwiftMailer does currently not work with IDN domains, this function therefore converts the domains
-	 *
-	 * FIXME: Remove this once SwiftMailer supports IDN
-	 *
-	 * @param string $email
-	 * @return string Converted mail address if `idn_to_ascii` exists
-	 */
-	protected function convertEmail(string $email): string {
-		if (!function_exists('idn_to_ascii') || !defined('INTL_IDNA_VARIANT_UTS46') || strpos($email, '@') === false) {
-			return $email;
-		}
-
-		[$name, $domain] = explode('@', $email, 2);
-		$domain = idn_to_ascii($domain, 0, INTL_IDNA_VARIANT_UTS46);
-		return $name.'@'.$domain;
-	}
-
-	protected function getInstance(): \Swift_Mailer {
+	protected function getInstance(): MailerInterface {
 		if (!is_null($this->instance)) {
 			return $this->instance;
 		}
@@ -255,31 +277,47 @@ class Mailer implements IMailer {
 				break;
 		}
 
-		return new \Swift_Mailer($transport);
+		return new SymfonyMailer($transport);
 	}
 
 	/**
 	 * Returns the SMTP transport
 	 *
-	 * @return \Swift_SmtpTransport
+	 * Only supports ssl/tls
+	 * starttls is not enforcable with Symfony Mailer but might be available
+	 * via the automatic config (Symfony Mailer internal)
+	 *
+	 * @return EsmtpTransport
 	 */
-	protected function getSmtpInstance(): \Swift_SmtpTransport {
-		$transport = new \Swift_SmtpTransport();
-		$transport->setTimeout($this->config->getSystemValue('mail_smtptimeout', 10));
-		$transport->setHost($this->config->getSystemValue('mail_smtphost', '127.0.0.1'));
-		$transport->setPort($this->config->getSystemValue('mail_smtpport', 25));
+	protected function getSmtpInstance(): EsmtpTransport {
+		// either null or true - if nothing is passed, let the symfony mailer figure out the configuration by itself
+		$mailSmtpsecure = ($this->config->getSystemValue('mail_smtpsecure', null) === 'ssl') ? true : null;
+		$transport = new EsmtpTransport(
+			$this->config->getSystemValue('mail_smtphost', '127.0.0.1'),
+			(int)$this->config->getSystemValue('mail_smtpport', 25),
+			$mailSmtpsecure,
+			null,
+			$this->logger
+		);
+		/** @var SocketStream $stream */
+		$stream = $transport->getStream();
+		/** @psalm-suppress InternalMethod */
+		$stream->setTimeout($this->config->getSystemValue('mail_smtptimeout', 10));
+
 		if ($this->config->getSystemValue('mail_smtpauth', false)) {
 			$transport->setUsername($this->config->getSystemValue('mail_smtpname', ''));
 			$transport->setPassword($this->config->getSystemValue('mail_smtppassword', ''));
-			$transport->setAuthMode($this->config->getSystemValue('mail_smtpauthtype', 'LOGIN'));
-		}
-		$smtpSecurity = $this->config->getSystemValue('mail_smtpsecure', '');
-		if (!empty($smtpSecurity)) {
-			$transport->setEncryption($smtpSecurity);
 		}
+
 		$streamingOptions = $this->config->getSystemValue('mail_smtpstreamoptions', []);
 		if (is_array($streamingOptions) && !empty($streamingOptions)) {
-			$transport->setStreamOptions($streamingOptions);
+			/** @psalm-suppress InternalMethod */
+			$currentStreamingOptions = $stream->getStreamOptions();
+
+			$currentStreamingOptions = array_merge_recursive($currentStreamingOptions, $streamingOptions);
+
+			/** @psalm-suppress InternalMethod */
+			$stream->setStreamOptions($currentStreamingOptions);
 		}
 
 		$overwriteCliUrl = parse_url(
@@ -297,9 +335,9 @@ class Mailer implements IMailer {
 	/**
 	 * Returns the sendmail transport
 	 *
-	 * @return \Swift_SendmailTransport
+	 * @return SendmailTransport
 	 */
-	protected function getSendMailInstance(): \Swift_SendmailTransport {
+	protected function getSendMailInstance(): SendmailTransport {
 		switch ($this->config->getSystemValue('mail_smtpmode', 'smtp')) {
 			case 'qmail':
 				$binaryPath = '/var/qmail/bin/sendmail';
@@ -322,6 +360,6 @@ class Mailer implements IMailer {
 				break;
 		}
 
-		return new \Swift_SendmailTransport($binaryPath . $binaryParam);
+		return new SendmailTransport($binaryPath . $binaryParam, null, $this->logger);
 	}
 }
diff --git a/lib/private/Mail/Message.php b/lib/private/Mail/Message.php
index 3313b39e2e2..01beefcc6d6 100644
--- a/lib/private/Mail/Message.php
+++ b/lib/private/Mail/Message.php
@@ -35,64 +35,67 @@ use OCP\Mail\Headers\AutoSubmitted;
 use OCP\Mail\IAttachment;
 use OCP\Mail\IEMailTemplate;
 use OCP\Mail\IMessage;
-use Swift_Message;
+use Symfony\Component\Mime\Address;
+use Symfony\Component\Mime\Email;
+use Symfony\Component\Mime\Exception\InvalidArgumentException;
+use Symfony\Component\Mime\Exception\RfcComplianceException;
 
 /**
- * Class Message provides a wrapper around SwiftMail
+ * Class Message provides a wrapper around Symfony\Component\Mime\Email (Used to be around SwiftMail)
  *
  * @package OC\Mail
  */
 class Message implements IMessage {
-	/** @var Swift_Message */
-	private $swiftMessage;
-	/** @var bool */
-	private $plainTextOnly;
+	private Email $symfonyEmail;
+	private bool $plainTextOnly;
 
-	public function __construct(Swift_Message $swiftMessage, bool $plainTextOnly) {
-		$this->swiftMessage = $swiftMessage;
+	private array $to;
+	private array $from;
+	private array $replyTo;
+	private array $cc;
+	private array $bcc;
+
+	public function __construct(Email $symfonyEmail, bool $plainTextOnly) {
+		$this->symfonyEmail = $symfonyEmail;
 		$this->plainTextOnly = $plainTextOnly;
+		$this->to = [];
+		$this->from = [];
+		$this->replyTo = [];
+		$this->cc = [];
+		$this->bcc = [];
 	}
 
 	/**
-	 * @param IAttachment $attachment
 	 * @return $this
 	 * @since 13.0.0
 	 */
 	public function attach(IAttachment $attachment): IMessage {
 		/** @var Attachment $attachment */
-		$this->swiftMessage->attach($attachment->getSwiftAttachment());
+		$attachment->attach($this->symfonyEmail);
 		return $this;
 	}
 
 	/**
-	 * SwiftMailer does currently not work with IDN domains, this function therefore converts the domains
-	 * FIXME: Remove this once SwiftMailer supports IDN
+	 * Converts the [['displayName' => 'email'], ['displayName2' => 'email2']] arrays to valid Adresses
 	 *
-	 * @param array $addresses Array of mail addresses, key will get converted
-	 * @return array Converted addresses if `idn_to_ascii` exists
+	 * @param array $addresses Array of mail addresses
+	 * @return Address[]
+	 * @throws RfcComplianceException|InvalidArgumentException
 	 */
 	protected function convertAddresses(array $addresses): array {
-		if (!function_exists('idn_to_ascii') || !defined('INTL_IDNA_VARIANT_UTS46')) {
-			return $addresses;
-		}
-
 		$convertedAddresses = [];
 
-		foreach ($addresses as $email => $readableName) {
-			$parsableEmail = is_numeric($email) ? $readableName : $email;
-			if (strpos($parsableEmail, '@') === false) {
-				$convertedAddresses[$parsableEmail] = $readableName;
-				continue;
-			}
+		if (empty($addresses)) {
+			return [];
+		}
 
-			[$name, $domain] = explode('@', $parsableEmail, 2);
-			$domain = idn_to_ascii($domain, 0, INTL_IDNA_VARIANT_UTS46);
+		array_walk($addresses, function ($readableName, $email) use (&$convertedAddresses) {
 			if (is_numeric($email)) {
-				$convertedAddresses[] = $name . '@' . $domain;
+				$convertedAddresses[] = new Address($readableName);
 			} else {
-				$convertedAddresses[$name . '@' . $domain] = $readableName;
+				$convertedAddresses[] = new Address($email, $readableName);
 			}
-		}
+		});
 
 		return $convertedAddresses;
 	}
@@ -106,41 +109,32 @@ class Message implements IMessage {
 	 * @return $this
 	 */
 	public function setFrom(array $addresses): IMessage {
-		$addresses = $this->convertAddresses($addresses);
-
-		$this->swiftMessage->setFrom($addresses);
+		$this->from = $addresses;
 		return $this;
 	}
 
 	/**
 	 * Get the from address of this message.
-	 *
-	 * @return array
 	 */
 	public function getFrom(): array {
-		return $this->swiftMessage->getFrom() ?? [];
+		return $this->from;
 	}
 
 	/**
 	 * Set the Reply-To address of this message
 	 *
-	 * @param array $addresses
 	 * @return $this
 	 */
 	public function setReplyTo(array $addresses): IMessage {
-		$addresses = $this->convertAddresses($addresses);
-
-		$this->swiftMessage->setReplyTo($addresses);
+		$this->replyTo = $addresses;
 		return $this;
 	}
 
 	/**
 	 * Returns the Reply-To address of this message
-	 *
-	 * @return string
 	 */
-	public function getReplyTo(): string {
-		return $this->swiftMessage->getReplyTo();
+	public function getReplyTo(): array {
+		return $this->replyTo;
 	}
 
 	/**
@@ -150,19 +144,15 @@ class Message implements IMessage {
 	 * @return $this
 	 */
 	public function setTo(array $recipients): IMessage {
-		$recipients = $this->convertAddresses($recipients);
-
-		$this->swiftMessage->setTo($recipients);
+		$this->to = $recipients;
 		return $this;
 	}
 
 	/**
 	 * Get the to address of this message.
-	 *
-	 * @return array
 	 */
 	public function getTo(): array {
-		return $this->swiftMessage->getTo() ?? [];
+		return $this->to;
 	}
 
 	/**
@@ -172,19 +162,15 @@ class Message implements IMessage {
 	 * @return $this
 	 */
 	public function setCc(array $recipients): IMessage {
-		$recipients = $this->convertAddresses($recipients);
-
-		$this->swiftMessage->setCc($recipients);
+		$this->cc = $recipients;
 		return $this;
 	}
 
 	/**
 	 * Get the cc address of this message.
-	 *
-	 * @return array
 	 */
 	public function getCc(): array {
-		return $this->swiftMessage->getCc() ?? [];
+		return $this->cc;
 	}
 
 	/**
@@ -194,104 +180,119 @@ class Message implements IMessage {
 	 * @return $this
 	 */
 	public function setBcc(array $recipients): IMessage {
-		$recipients = $this->convertAddresses($recipients);
-
-		$this->swiftMessage->setBcc($recipients);
+		$this->bcc = $recipients;
 		return $this;
 	}
 
 	/**
 	 * Get the Bcc address of this message.
-	 *
-	 * @return array
 	 */
 	public function getBcc(): array {
-		return $this->swiftMessage->getBcc() ?? [];
+		return $this->bcc;
 	}
 
 	/**
 	 * Set the subject of this message.
 	 *
-	 * @param string $subject
-	 * @return IMessage
+	 * @return $this
 	 */
 	public function setSubject(string $subject): IMessage {
-		$this->swiftMessage->setSubject($subject);
+		$this->symfonyEmail->subject($subject);
 		return $this;
 	}
 
 	/**
 	 * Get the from subject of this message.
-	 *
-	 * @return string
 	 */
 	public function getSubject(): string {
-		return $this->swiftMessage->getSubject();
+		return $this->symfonyEmail->getSubject() ?? '';
 	}
 
 	/**
 	 * Set the plain-text body of this message.
-	 *
-	 * @param string $body
 	 * @return $this
 	 */
 	public function setPlainBody(string $body): IMessage {
-		$this->swiftMessage->setBody($body);
+		$this->symfonyEmail->text($body);
 		return $this;
 	}
 
 	/**
 	 * Get the plain body of this message.
-	 *
-	 * @return string
 	 */
 	public function getPlainBody(): string {
-		return $this->swiftMessage->getBody();
+		/** @var string $body */
+		$body = $this->symfonyEmail->getTextBody() ?? '';
+		return $body;
 	}
 
 	/**
 	 * Set the HTML body of this message. Consider also sending a plain-text body instead of only an HTML one.
-	 *
-	 * @param string $body
 	 * @return $this
 	 */
-	public function setHtmlBody($body) {
+	public function setHtmlBody(string $body): IMessage {
 		if (!$this->plainTextOnly) {
-			$this->swiftMessage->addPart($body, 'text/html');
+			$this->symfonyEmail->html($body);
 		}
 		return $this;
 	}
 
 	/**
-	 * Get's the underlying SwiftMessage
-	 * @param Swift_Message $swiftMessage
+	 * Set the underlying Email intance
 	 */
-	public function setSwiftMessage(Swift_Message $swiftMessage): void {
-		$this->swiftMessage = $swiftMessage;
+	public function setSymfonyEmail(Email $symfonyEmail): void {
+		$this->symfonyEmail = $symfonyEmail;
 	}
 
 	/**
-	 * Get's the underlying SwiftMessage
-	 * @return Swift_Message
+	 * Get the underlying Email instance
 	 */
-	public function getSwiftMessage(): Swift_Message {
-		return $this->swiftMessage;
+	public function getSymfonyEmail(): Email {
+		return $this->symfonyEmail;
 	}
 
 	/**
-	 * @param string $body
-	 * @param string $contentType
 	 * @return $this
 	 */
-	public function setBody($body, $contentType) {
+	public function setBody(string $body, string $contentType): IMessage {
 		if (!$this->plainTextOnly || $contentType !== 'text/html') {
-			$this->swiftMessage->setBody($body, $contentType);
+			if ($contentType === 'text/html') {
+				$this->symfonyEmail->html($body);
+			} else {
+				$this->symfonyEmail->text($body);
+			}
 		}
 		return $this;
 	}
 
 	/**
-	 * @param IEMailTemplate $emailTemplate
+	 * Set the recipients on the symphony email
+	 *
+	 * Since
+	 *
+	 * setTo
+	 * setFrom
+	 * setReplyTo
+	 * setCc
+	 * setBcc
+	 *
+	 * could throw a \Symfony\Component\Mime\Exception\RfcComplianceException
+	 * or a \Symfony\Component\Mime\Exception\InvalidArgumentException
+	 * we wrap the calls here. We then have the validation errors all in one place and can
+	 * throw shortly before \OC\Mail\Mailer::send
+	 *
+	 * @return void
+	 * @throws InvalidArgumentException|RfcComplianceException
+	 */
+	public function setRecipients() {
+		$this->symfonyEmail->to(...$this->convertAddresses($this->getTo()));
+		$this->symfonyEmail->from(...$this->convertAddresses($this->getFrom()));
+		$this->symfonyEmail->replyTo(...$this->convertAddresses($this->getReplyTo()));
+		$this->symfonyEmail->cc(...$this->convertAddresses($this->getCc()));
+		$this->symfonyEmail->bcc(...$this->convertAddresses($this->getBcc()));
+	}
+
+	/**
 	 * @return $this
 	 */
 	public function useTemplate(IEMailTemplate $emailTemplate): IMessage {
@@ -311,7 +312,7 @@ class Message implements IMessage {
 	 * @return $this
 	 */
 	public function setAutoSubmitted(string $value): IMessage {
-		$headers = $this->swiftMessage->getHeaders();
+		$headers = $this->symfonyEmail->getHeaders();
 
 		if ($headers->has(AutoSubmitted::HEADER)) {
 			// if the header already exsists, remove it.
@@ -319,6 +320,7 @@ class Message implements IMessage {
 			// of the interface \Swift_Mime_Header, however the
 			// interface doesn't, and this makes the static-code
 			// analysis unhappy.
+			// @todo check if symfony mailer can modify the autosubmitted header
 			$headers->remove(AutoSubmitted::HEADER);
 		}
 
@@ -334,9 +336,9 @@ class Message implements IMessage {
 	 * @return string
 	 */
 	public function getAutoSubmitted(): string {
-		$headers = $this->swiftMessage->getHeaders();
+		$headers = $this->symfonyEmail->getHeaders();
 
 		return $headers->has(AutoSubmitted::HEADER) ?
-			$headers->get(AutoSubmitted::HEADER)->toString() : AutoSubmitted::VALUE_NO;
+			$headers->get(AutoSubmitted::HEADER)->getBodyAsString() : AutoSubmitted::VALUE_NO;
 	}
 }
diff --git a/lib/public/Mail/IMailer.php b/lib/public/Mail/IMailer.php
index 325abd9301e..db46401a3d8 100644
--- a/lib/public/Mail/IMailer.php
+++ b/lib/public/Mail/IMailer.php
@@ -96,7 +96,7 @@ interface IMailer {
 	public function send(IMessage $message): array;
 
 	/**
-	 * Checks if an e-mail address is valid
+	 * @deprecated 26.0.0
 	 *
 	 * @param string $email Email address to be validated
 	 * @return bool True if the mail address is valid, false otherwise