diff --git a/modules/symfony_mailer_bc/src/Plugin/EmailBuilder/WebformEmailBuilder.php b/modules/symfony_mailer_bc/src/Plugin/EmailBuilder/WebformEmailBuilder.php
new file mode 100644
index 0000000..d924ba9
--- /dev/null
+++ b/modules/symfony_mailer_bc/src/Plugin/EmailBuilder/WebformEmailBuilder.php
@@ -0,0 +1,27 @@
+<?php
+
+namespace Drupal\symfony_mailer_bc\Plugin\EmailBuilder;
+
+use Drupal\symfony_mailer\EmailInterface;
+use Drupal\symfony_mailer\Plugin\EmailBuilder\LegacyEmailBuilder;
+
+/**
+ * Defines the Email Builder plug-in for webform module.
+ *
+ * @EmailBuilder(
+ *   id = "webform"
+ * )
+ */
+class WebformEmailBuilder extends LegacyEmailBuilder {
+
+  /**
+   * {@inheritDoc}
+   */
+  public function createParams(EmailInterface $email, array $legacy_message = NULL) {
+    parent::createParams($email, $legacy_message);
+    if (isset($legacy_message['params']['attachments'])) {
+      $email->setParam('attachments', $legacy_message['params']['attachments']);
+    }
+  }
+
+}
diff --git a/src/Email.php b/src/Email.php
index 42d2ad0..eb3a4fb 100644
--- a/src/Email.php
+++ b/src/Email.php
@@ -600,4 +600,12 @@ class Email implements InternalEmailInterface {
     }
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function attach(string $content, string $name = NULL, string $mimeType = NULL) {
+    $this->inner->attach($content, $name, $mimeType);
+    return $this;
+  }
+
 }
diff --git a/src/EmailInterface.php b/src/EmailInterface.php
index 6ebb5dd..205bbea 100644
--- a/src/EmailInterface.php
+++ b/src/EmailInterface.php
@@ -373,4 +373,18 @@ interface EmailInterface extends BaseEmailInterface {
    */
   public function getTransportDsn();
 
+  /**
+   * Adds an attachment by content.
+   *
+   * @param string $content
+   *   The content of the file.
+   * @param string|null $name
+   *   (optional) The file name. Defaults to the base name of the path.
+   * @param string|null $mimeType
+   *   (optional) The mime type. If omitted, the type will be guessed.
+   *
+   * @return $this
+   */
+  public function attach(string $content, ?string $name = NULL, ?string $mimeType = NULL);
+
 }
diff --git a/src/LegacyMailerHelper.php b/src/LegacyMailerHelper.php
index c953027..64149d0 100644
--- a/src/LegacyMailerHelper.php
+++ b/src/LegacyMailerHelper.php
@@ -86,7 +86,12 @@ class LegacyMailerHelper implements LegacyMailerHelperInterface {
     // Attachments.
     $attachments = $message['params']['attachments'] ?? [];
     foreach ($attachments as $attachment) {
-      $email->attachFromPath($attachment['filepath'], $attachment['filename'] ?? NULL, $attachment['filemime'] ?? NULL);
+      if (!empty($attachment['filecontent'])) {
+        $email->attach($attachment["filecontent"], $attachment['filename'] ?? NULL, $attachment['filemime'] ?? NULL);
+      }
+      else {
+        $email->attachFromPath($attachment['filepath'], $attachment['filename'] ?? NULL, $attachment['filemime'] ?? NULL);
+      }
     }
 
     // Address headers.
diff --git a/src/Plugin/EmailAdjuster/AttachmentEmailAdjuster.php b/src/Plugin/EmailAdjuster/AttachmentEmailAdjuster.php
new file mode 100644
index 0000000..0adc2f3
--- /dev/null
+++ b/src/Plugin/EmailAdjuster/AttachmentEmailAdjuster.php
@@ -0,0 +1,198 @@
+<?php
+
+namespace Drupal\symfony_mailer\Plugin\EmailAdjuster;
+
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\symfony_mailer\Processor\EmailAdjusterBase;
+use Drupal\symfony_mailer\EmailInterface;
+use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
+use Drupal\Core\File\FileSystemInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+use Drupal\Component\Utility\NestedArray;
+use Psr\Log\LoggerInterface;
+
+/**
+ * Attachments Email Adjuster.
+ *
+ * @EmailAdjuster(
+ *   id = "mailer_attachments",
+ *   label = @Translation("Attachments"),
+ *   description = @Translation("Set mail attachments."),
+ *   weight = 100,
+ * )
+ */
+class AttachmentEmailAdjuster extends EmailAdjusterBase implements ContainerFactoryPluginInterface {
+
+  /**
+   * The file system service.
+   *
+   * @var \Drupal\Core\File\FileSystemInterface
+   */
+  protected $fileSystem;
+
+  /**
+   * The logger.
+   *
+   * @var \Psr\Log\LoggerInterface
+   */
+  protected $logger;
+
+  /**
+   * Array of allowed paths.
+   *
+   * @var string[]
+   */
+  protected $allowedPaths;
+
+  /**
+   * Constructs a new AttachmentEmailAdjuster object.
+   *
+   * @param array $configuration
+   *   A configuration array containing information about the plugin instance.
+   * @param string $plugin_id
+   *   The plugin ID for the plugin instance.
+   * @param mixed $plugin_definition
+   *   The plugin implementation definition.
+   * @param \Drupal\Core\File\FileSystemInterface $file_system
+   *   The configuration factory.
+   */
+  public function __construct(array $configuration, $plugin_id, $plugin_definition, FileSystemInterface $file_system, LoggerInterface $logger) {
+    parent::__construct($configuration, $plugin_id, $plugin_definition);
+
+    $this->configuration = NestedArray::mergeDeep($this->defaultConfiguration(), $configuration);
+    $this->fileSystem = $file_system;
+    $this->logger = $logger;
+
+    $this->allowedPaths = [];
+
+    if ($this->configuration['public_files']) {
+      $this->allowedPaths['public'] = $this->fileSystem->realpath('public://');
+    }
+
+    if ($this->configuration['private_files']) {
+      $this->allowedPaths['private'] = $this->fileSystem->realpath('private://');
+    }
+
+    if ($this->configuration['temporary_files']) {
+      $this->allowedPaths['temporary'] = $this->fileSystem->realpath('temporary://');
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
+    return new static(
+      $configuration,
+      $plugin_id,
+      $plugin_definition,
+      $container->get('file_system'),
+      $container->get('logger.factory')->get('symfony_mailer')
+    );
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function preRender(EmailInterface $email) {
+    try {
+      if ($attachments = $email->getParam('attachments')) {
+        foreach ($attachments as $attachment) {
+          if (!isset($attachment['filepath'])) {
+            continue;
+          }
+
+          if ($file_path = $this->fileSystem->realpath($attachment['filepath'])) {
+            foreach ($this->allowedPaths as $scheme => $allowed_path) {
+              if (\strpos($file_path, $allowed_path) === 0) {
+                $email->attachFromPath(
+                  $file_path,
+                  $attachment['filename'] ?? null,
+                  $attachment['filemime'] ?? null
+                );
+                break;
+              }
+            }
+          }
+          elseif ($this->urlAllowed() && $this->configuration['url_files'] && \filter_var($attachment['filepath'], FILTER_VALIDATE_URL)) {
+            $email->attachFromPath(
+              $attachment['filepath']
+            );
+          }
+          else {
+            $this->logger->warning($this->t('Attachment %file not attached to email %subject for %recepient', [
+              '%file' => $attachment['filepath'],
+              '%subject' => (string) $email->getSubject(),
+              '%recepient' => \reset($email->getTo())->getEmail()
+            ]));
+          }
+        }
+      }
+    } catch (\Exception $e) {
+      watchdog_exception('symfony_mailer', $e);
+    }
+  }
+
+  /**
+   * Gets default configuration for this plugin.
+   *
+   * @return array
+   *   An associative array with the default configuration.
+   */
+  public function defaultConfiguration() {
+    return [
+      'public_files' => TRUE,
+      'private_files' => FALSE,
+      'temporary_files' => TRUE,
+      'url_files' => FALSE,
+    ];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function settingsForm(array $form, FormStateInterface $form_state) {
+    $form['public_files'] = [
+      '#type' => 'checkbox',
+      '#title' => $this->t('Public files'),
+      '#description' => $this->t('Allow attachments to be files within public files.'),
+      '#default_value' => $this->configuration['public_files'],
+    ];
+
+    $form['private_files'] = [
+      '#type' => 'checkbox',
+      '#title' => $this->t('Private files'),
+      '#description' => $this->t('Allow attachments to be files within private files.'),
+      '#default_value' => $this->configuration['private_files'],
+    ];
+
+    $form['temporary_files'] = [
+      '#type' => 'checkbox',
+      '#title' => $this->t('Temporary files'),
+      '#description' => $this->t('Allow attachments to be files within temporary files.'),
+      '#default_value' => $this->configuration['temporary_files'],
+    ];
+
+    $form['url_files'] = [
+      '#type' => 'checkbox',
+      '#title' => $this->t('Files by URL'),
+      '#description' => $this->t('Allow attachments to be remote files accessed by URL.'),
+      '#default_value' => $this->urlAllowed()
+        ? $this->configuration['url_files']
+        : FALSE,
+    ];
+
+    if (!$this->urlAllowed()) {
+      $form['url_files']['#attributes']['disabled'] = 'disabled';
+    }
+
+    return $form;
+  }
+
+  /**
+   * Check if system is set up to handle url with fopen.
+   */
+  protected function urlAllowed() {
+    return \ini_get('allow_url_fopen');
+  }
+}