diff --git a/phpBB/phpbb/messenger/method/email.php b/phpBB/phpbb/messenger/method/email.php
index 6fb3e20e68..3b580b6a69 100644
--- a/phpBB/phpbb/messenger/method/email.php
+++ b/phpBB/phpbb/messenger/method/email.php
@@ -13,6 +13,8 @@
 
 namespace phpbb\messenger\method;
 
+use Symfony\Component\Mailer\Exception\TransportExceptionInterface;
+use Symfony\Component\Mailer\MailerInterface;
 use Symfony\Component\Mailer\Transport;
 use Symfony\Component\Mailer\Mailer;
 use Symfony\Component\Mailer\Transport\AbstractTransport;
@@ -275,7 +277,6 @@ class email extends base
 	 */
 	protected function build_headers(): void
 	{
-
 		$board_contact = trim($this->config['board_contact']);
 		$contact_name = html_entity_decode($this->config['board_contact_name'], ENT_COMPAT);
 
@@ -317,7 +318,6 @@ class email extends base
 		{
 			$this->header($header, $value);
 		}
-
 	}
 
 	/**
@@ -408,7 +408,7 @@ class email extends base
 
 		$package_size = $queue_data[$queue_object_name]['package_size'] ?? 0;
 		$num_items = (!$package_size || $messages_count < $package_size) ? $messages_count : $package_size;
-		$mailer = new Mailer($this->transport);
+		$mailer = $this->get_mailer();
 
 		for ($i = 0; $i < $num_items; $i++)
 		{
@@ -437,7 +437,7 @@ class email extends base
 				{
 					$mailer->send($email);
 				}
-				catch (\Symfony\Component\Mailer\Exception\TransportExceptionInterface $e)
+				catch (TransportExceptionInterface $e)
 				{
 					$this->error($e->getDebug());
 					continue;
@@ -452,6 +452,16 @@ class email extends base
 		}
 	}
 
+	/**
+	 * Get mailer object
+	 *
+	 * @return MailerInterface Symfony Mailer object
+	 */
+	protected function get_mailer(): MailerInterface
+	{
+		return new Mailer($this->transport);
+	}
+
 	/**
 	 * Get mailer transport object
 	 *
@@ -506,7 +516,7 @@ class email extends base
 		// Send message ...
 		if (!$this->use_queue)
 		{
-			$mailer = new Mailer($this->transport);
+			$mailer = $this->get_mailer();
 
 			$subject = $this->subject;
 			$msg = $this->msg;
@@ -540,7 +550,7 @@ class email extends base
 			{
 				$mailer->send($this->email);
 			}
-			catch (\Symfony\Component\Mailer\Exception\TransportExceptionInterface $e)
+			catch (TransportExceptionInterface $e)
 			{
 				$this->error($e->getDebug());
 				return false;
diff --git a/tests/messenger/method_email_test.php b/tests/messenger/method_email_test.php
index a1d8256070..e0dfae93b5 100644
--- a/tests/messenger/method_email_test.php
+++ b/tests/messenger/method_email_test.php
@@ -19,45 +19,65 @@ use phpbb\messenger\queue;
 use phpbb\path_helper;
 use phpbb\symfony_request;
 use phpbb\template\assets_bag;
+use Symfony\Component\Mime\RawMessage;
 
 class phpbb_messenger_method_email_test extends \phpbb_test_case
 {
+	protected $assets_bag;
+	protected $cache_path;
 	protected config $config;
+	protected $dispatcher;
+	protected $extension_manager;
+	protected $language;
+	protected $log;
+	protected $path_helper;
 	protected queue $queue;
 	protected $request;
+	protected $twig_extensions_collection;
+	protected $twig_lexer;
+	protected $user;
 
 	public function setUp(): void
 	{
-		global $phpbb_root_path, $phpEx;
+		global $config, $request, $symfony_request, $user, $phpbb_root_path, $phpEx;
 
-		$assets_bag = new assets_bag();
-		$cache_path = $phpbb_root_path . 'cache/' . PHPBB_ENVIRONMENT . '/twig';
-		$this->config = new config([]);
-		$dispatcher = new \phpbb_mock_event_dispatcher();
-		$filesystem = new \phpbb\filesystem\filesystem();
-		$language = new language(new language_file_loader($phpbb_root_path, $phpEx));
+		$this->assets_bag = new assets_bag();
+		$this->cache_path = $phpbb_root_path . 'cache/' . PHPBB_ENVIRONMENT . '/twig';
+		$this->config = new config([
+			'force_server_vars' => false,
+		]);
+		$config = $this->config;
+		$this->dispatcher = $this->getMockBuilder('\phpbb\event\dispatcher')
+			->disableOriginalConstructor()
+			->getMock();
+		$this->filesystem = new \phpbb\filesystem\filesystem();
+		$this->language = new language(new language_file_loader($phpbb_root_path, $phpEx));
 		$this->queue = $this->createMock(queue::class);
 		$this->request = new phpbb_mock_request();
-		$user = new \phpbb\user($language, '\phpbb\datetime');
-		$path_helper = new path_helper(
-			new symfony_request(
-				new phpbb_mock_request()
-			),
+		$request = $this->request;
+		$this->symfony_request = new symfony_request(new phpbb_mock_request());
+		$symfony_request = $this->symfony_request;
+		$this->user = new \phpbb\user($this->language, '\phpbb\datetime');
+		$user = $this->user;
+		$user->page['root_script_path'] = 'phpbb/';
+		$this->user->host = 'yourdomain.com';
+		$this->path_helper = new path_helper(
+			$this->symfony_request,
 			$this->request,
 			$phpbb_root_path,
 			$phpEx
 		);
 		$phpbb_container = new phpbb_mock_container_builder;
-		$twig_extensions_collection = new \phpbb\di\service_collection($phpbb_container);
+		$this->twig_extensions_collection = new \phpbb\di\service_collection($phpbb_container);
 		$twig = new \phpbb\template\twig\environment(
-			$assets_bag,
+			$this->assets_bag,
 			$this->config,
-			$filesystem,
-			$path_helper,
-			$cache_path,
+			$this->filesystem,
+			$this->path_helper,
+			$this->cache_path,
 			null,
 			new \phpbb\template\twig\loader(''),
-			$dispatcher,
+			$this->dispatcher,
 			array(
 				'cache'			=> false,
 				'debug'			=> false,
@@ -65,8 +85,8 @@ class phpbb_messenger_method_email_test extends \phpbb_test_case
 				'autoescape'	=> false,
 			)
 		);
-		$twig_lexer = new \phpbb\template\twig\lexer($twig);
-		$extension_manager = new phpbb_mock_extension_manager(
+		$this->twig_lexer = new \phpbb\template\twig\lexer($twig);
+		$this->extension_manager = new phpbb_mock_extension_manager(
 			__DIR__ . '/',
 			array(
 				'vendor2/foo' => array(
@@ -76,23 +96,23 @@ class phpbb_messenger_method_email_test extends \phpbb_test_case
 				),
 			)
 		);
-		$log = $this->createMock(\phpbb\log\log_interface::class);
+		$this->log = $this->createMock(\phpbb\log\log_interface::class);
 
 		$this->method_email = new email(
-			$assets_bag,
+			$this->assets_bag,
 			$this->config,
-			$dispatcher,
-			$language,
+			$this->dispatcher,
+			$this->language,
 			$this->queue,
-			$path_helper,
+			$this->path_helper,
 			$this->request,
-			$twig_extensions_collection,
-			$twig_lexer,
-			$user,
+			$this->twig_extensions_collection,
+			$this->twig_lexer,
+			$this->user,
 			$phpbb_root_path,
-			$cache_path,
-			$extension_manager,
-			$log
+			$this->cache_path,
+			$this->extension_manager,
+			$this->log
 		);
 	}
 
@@ -200,6 +220,17 @@ class phpbb_messenger_method_email_test extends \phpbb_test_case
 		$this->assertEmpty($email->getTo());
 	}
 
+	public function test_get_mailer()
+	{
+		$email_reflection = new \ReflectionClass($this->method_email);
+		$this->method_email->init();
+		$this->method_email->set_transport();
+		$mailer_method = $email_reflection->getMethod('get_mailer');
+
+		$mailer = $mailer_method->invoke($this->method_email);
+		$this->assertInstanceOf(\Symfony\Component\Mailer\Mailer::class, $mailer);
+	}
+
 	public function test_set_addresses()
 	{
 		$email_reflection = new \ReflectionClass($this->method_email);
@@ -384,4 +415,375 @@ class phpbb_messenger_method_email_test extends \phpbb_test_case
 		$this->assertNotEmpty($email->getSubject());
 		$this->assertEquals('Reply to test email', $email->getSubject());
 	}
+
+	public function test_anti_abuse_headers()
+	{
+		$email_reflection = new \ReflectionClass($this->method_email);
+		$headers_property = $email_reflection->getProperty('headers');
+		$this->method_email->init();
+
+		/** @var \Symfony\Component\Mime\Header\Headers $headers */
+		$headers = $headers_property->getValue($this->method_email);
+
+		$this->config->set('server_name', 'yourdomain.com');
+		$this->user->data['user_id'] = 2;
+		$this->user->data['username'] = 'admin';
+		$this->user->ip = '127.0.0.1';
+
+		$this->assertEmpty($headers->toArray());
+		$this->method_email->anti_abuse_headers($this->config, $this->user);
+
+		$this->assertEquals(
+			[
+				'X-AntiAbuse: Board servername - yourdomain.com',
+				'X-AntiAbuse: User_id - 2',
+				'X-AntiAbuse: Username - admin',
+				'X-AntiAbuse: User IP - 127.0.0.1',
+			],
+			$headers->toArray()
+		);
+	}
+
+	public function test_set_mail_priority()
+	{
+		$email_reflection = new \ReflectionClass($this->method_email);
+		$email_property = $email_reflection->getProperty('email');
+		$this->method_email->init();
+		/** @var \Symfony\Component\Mime\Email $email */
+		$email = $email_property->getValue($this->method_email);
+		$this->assertNotNull($email);
+
+		// Default priority
+		$this->assertEquals(\Symfony\Component\Mime\Email::PRIORITY_NORMAL, $email->getPriority());
+
+		// Highest priority
+		$this->method_email->set_mail_priority(\Symfony\Component\Mime\Email::PRIORITY_HIGHEST);
+		$this->assertEquals(\Symfony\Component\Mime\Email::PRIORITY_HIGHEST, $email->getPriority());
+	}
+
+	public function test_process_queue_not_enabled()
+	{
+		$this->method_email->init();
+
+		$queue_data = [
+			'email'	=> [
+				'data'	=> [
+					'message_one',
+					'message_two',
+				]
+			]
+		];
+
+		// Process queue will remove emails if email method is not enabled
+		$this->method_email->process_queue($queue_data);
+		$this->assertEmpty($queue_data);
+	}
+
+	public function test_process_queue()
+	{
+		global $phpbb_root_path;
+
+		$this->config->set('email_enable', true);
+		$this->user->data['user_id'] = 2;
+		$this->user->session_id = 'abcdef';
+
+		$this->method_email = $this->getMockBuilder($this->method_email::class)
+			->setConstructorArgs([$this->assets_bag,
+				$this->config,
+				$this->dispatcher,
+				$this->language,
+				$this->queue,
+				$this->path_helper,
+				$this->request,
+				$this->twig_extensions_collection,
+				$this->twig_lexer,
+				$this->user,
+				$phpbb_root_path,
+				$this->cache_path,
+				$this->extension_manager,
+				$this->log
+			])
+			->onlyMethods(['get_mailer'])
+			->getMock();
+
+		$mailer_mock = $this->getMockBuilder(\Symfony\Component\Mailer\MailerInterface::class)
+			->disableOriginalConstructor()
+			->onlyMethods(['send'])
+			->getMock();
+		$sent_emails = 0;
+		$mailer_mock->method('send')
+			->willReturnCallback(function(RawMessage $mail) use(&$sent_emails) {
+				if ($mail->toString() === 'throw_exception')
+				{
+					throw new \Symfony\Component\Mailer\Exception\TransportException('exception');
+				}
+
+				$sent_emails++;
+			});
+		$this->method_email->method('get_mailer')->willReturn($mailer_mock);
+
+		$this->method_email->init();
+		$errors = [];
+		$this->log->method('add')
+			->willReturnCallback(function($mode, $user_id, $log_ip, $log_operation, $log_time = false, $additional_data = []) use (&$errors) {
+				$errors[] = $additional_data[0];
+			});
+
+		$this->dispatcher
+			->expects($this->atLeastOnce())
+			->method('trigger_event')
+			->willReturnCallback(function($event_name, $value_array) {
+				if ($event_name === 'core.notification_message_process' && $value_array['email']->toString() == 'message_three')
+				{
+					$value_array['break'] = true;
+				}
+
+				return $value_array;
+			});
+
+		$queue_data = [
+			'email'	=> [
+				'data'	=> [
+					['email' => new RawMessage('message_one')],
+					['email' => new RawMessage('message_two')],
+					['email' => new RawMessage('message_three')],
+					['email' => new RawMessage('throw_exception')],
+					['email' => new RawMessage('message_four')],
+				]
+			]
+		];
+
+		$this->assertEmpty($errors);
+		$this->method_email->process_queue($queue_data);
+		$this->assertEmpty($queue_data);
+		$this->assertEquals(3, $sent_emails);
+
+		$this->assertEquals(['<strong>EMAIL</strong><br><em></em><br><br><br>'], $errors);
+	}
+
+	public function test_send_break()
+	{
+		$this->dispatcher
+			->expects($this->atLeastOnce())
+			->method('trigger_event')
+			->willReturnCallback(function($event_name, $value_array) {
+				if ($event_name !== 'core.notification_message_email')
+				{
+					return $value_array;
+				}
+
+				$value_array['break'] = true;
+				return $value_array;
+			});
+
+		$this->config->set('board_email', 'admin@yourdomain.com');
+
+		$this->method_email->init();
+		$this->method_email->to('foo@bar.com');
+		$this->method_email->subject('Test email');
+		$this->method_email->template('test', 'en');
+
+		$this->method_email->send();
+	}
+
+	public function test_send_no_queue()
+	{
+		global $phpbb_root_path;
+
+		$this->config->set('email_enable', true);
+		$this->user->data['user_id'] = 2;
+		$this->user->session_id = 'abcdef';
+
+		$this->method_email = $this->getMockBuilder($this->method_email::class)
+			->setConstructorArgs([$this->assets_bag,
+				$this->config,
+				$this->dispatcher,
+				$this->language,
+				$this->queue,
+				$this->path_helper,
+				$this->request,
+				$this->twig_extensions_collection,
+				$this->twig_lexer,
+				$this->user,
+				$phpbb_root_path,
+				$this->cache_path,
+				$this->extension_manager,
+				$this->log
+			])
+			->onlyMethods(['get_mailer'])
+			->getMock();
+
+		$mailer_mock = $this->getMockBuilder(\Symfony\Component\Mailer\MailerInterface::class)
+			->disableOriginalConstructor()
+			->onlyMethods(['send'])
+			->getMock();
+		$sent_emails = 0;
+		$mailer_mock->method('send')
+			->willReturnCallback(function(RawMessage $mail) use(&$sent_emails) {
+				$sent_emails++;
+			});
+		$this->method_email->method('get_mailer')->willReturn($mailer_mock);
+
+		$this->config->set('board_email', 'admin@yourdomain.com');
+
+		$this->method_email->init();
+		$errors = [];
+		$this->log->method('add')
+			->willReturnCallback(function($mode, $user_id, $log_ip, $log_operation, $log_time = false, $additional_data = []) use (&$errors) {
+				$errors[] = $additional_data[0];
+			});
+
+		$this->dispatcher
+			->expects($this->atLeastOnce())
+			->method('trigger_event')
+			->willReturnCallback(function($event_name, $value_array) {
+				return $value_array;
+			});
+
+		$this->method_email->to('foo@bar.com');
+		$this->method_email->subject('Test email');
+		$this->method_email->template('test', 'en');
+
+		$this->assertTrue($this->method_email->send());
+		$this->assertEquals(1, $sent_emails);
+
+		$this->assertEmpty($errors);
+	}
+
+	public function test_send_exception()
+	{
+		global $phpbb_root_path;
+
+		$this->config->set('email_enable', true);
+		$this->user->data['user_id'] = 2;
+		$this->user->session_id = 'abcdef';
+
+		$this->method_email = $this->getMockBuilder($this->method_email::class)
+			->setConstructorArgs([$this->assets_bag,
+				$this->config,
+				$this->dispatcher,
+				$this->language,
+				$this->queue,
+				$this->path_helper,
+				$this->request,
+				$this->twig_extensions_collection,
+				$this->twig_lexer,
+				$this->user,
+				$phpbb_root_path,
+				$this->cache_path,
+				$this->extension_manager,
+				$this->log
+			])
+			->onlyMethods(['get_mailer'])
+			->getMock();
+
+		$mailer_mock = $this->getMockBuilder(\Symfony\Component\Mailer\MailerInterface::class)
+			->disableOriginalConstructor()
+			->onlyMethods(['send'])
+			->getMock();
+		$mailer_mock->method('send')
+			->willReturnCallback(function(RawMessage $mail) use(&$sent_emails) {
+				throw new \Symfony\Component\Mailer\Exception\TransportException('exception');
+			});
+		$this->method_email->method('get_mailer')->willReturn($mailer_mock);
+
+		$this->config->set('board_email', 'admin@yourdomain.com');
+
+		$this->method_email->init();
+		$errors = [];
+		$this->log->method('add')
+			->willReturnCallback(function($mode, $user_id, $log_ip, $log_operation, $log_time = false, $additional_data = []) use (&$errors) {
+				$errors[] = $additional_data[0];
+			});
+
+		$this->dispatcher
+			->expects($this->atLeastOnce())
+			->method('trigger_event')
+			->willReturnCallback(function($event_name, $value_array) {
+				return $value_array;
+			});
+
+		$this->method_email->to('foo@bar.com');
+		$this->method_email->subject('Test email');
+		$this->method_email->template('test', 'en');
+
+		$this->assertFalse($this->method_email->send());
+
+		$this->assertEquals(['<strong>EMAIL</strong><br><em></em><br><br><br>'], $errors);
+	}
+
+	public function test_send_queue()
+	{
+		global $phpbb_root_path;
+
+		$this->config->set('email_enable', true);
+		$this->config->set('email_package_size', 100);
+		$this->user->data['user_id'] = 2;
+		$this->user->session_id = 'abcdef';
+
+		$this->method_email = $this->getMockBuilder($this->method_email::class)
+			->setConstructorArgs([$this->assets_bag,
+				$this->config,
+				$this->dispatcher,
+				$this->language,
+				$this->queue,
+				$this->path_helper,
+				$this->request,
+				$this->twig_extensions_collection,
+				$this->twig_lexer,
+				$this->user,
+				$phpbb_root_path,
+				$this->cache_path,
+				$this->extension_manager,
+				$this->log
+			])
+			->onlyMethods(['get_mailer'])
+			->getMock();
+
+		$mailer_mock = $this->getMockBuilder(\Symfony\Component\Mailer\MailerInterface::class)
+			->disableOriginalConstructor()
+			->onlyMethods(['send'])
+			->getMock();
+		$mailer_mock->method('send')
+			->willReturnCallback(function(RawMessage $mail) use(&$sent_emails) {
+				throw new \Symfony\Component\Mailer\Exception\TransportException('exception');
+			});
+		$this->method_email->method('get_mailer')->willReturn($mailer_mock);
+
+		$this->config->set('board_email', 'admin@yourdomain.com');
+
+		$this->method_email->init();
+		$errors = [];
+		$this->log->method('add')
+			->willReturnCallback(function($mode, $user_id, $log_ip, $log_operation, $log_time = false, $additional_data = []) use (&$errors) {
+				$errors[] = $additional_data[0];
+			});
+
+		$this->dispatcher
+			->expects($this->atLeastOnce())
+			->method('trigger_event')
+			->willReturnCallback(function($event_name, $value_array) {
+				return $value_array;
+			});
+
+		// Mock queue methods
+		$this->queue->method('init')
+			->willReturnCallback(function(string $object, int $package_size) {
+				$this->assertEquals('email', $object);
+				$this->assertEquals($this->config['email_package_size'], $package_size);
+			});
+		$this->queue->method('put')
+			->willReturnCallback(function(string $object, array $message_data) {
+				$this->assertEquals('email', $object);
+				$this->assertStringContainsString('phpBB is correctly configured to send emails', $message_data['email']->getSubject());
+			});
+
+		$this->method_email->to('foo@bar.com');
+		$this->method_email->subject('Test email');
+		$this->method_email->template('test', 'en');
+
+		$this->assertTrue($this->method_email->send());
+
+		$this->assertEmpty($errors);
+	}
 }