tags.
      if ( $email['body'] === strip_tags($email['body']) // No html tags.
        && preg_match('/.' . $eol . './', $email['body']) // At least one embedded newline.
      ) {
        $email['body'] = '
' . $email['body'] . '
';
      }
    }
    // Theme with htmlmail.tpl.php.
    $body = theme('htmlmail', $email);
    $mime->setHTMLBody($body);
    // @todo Change to drupal_html_to_text when issue #299138 gets resolved.
    $mime->setTXTBody(mailsystem_html_to_text($body));
    $message['MailMIME'] = &$mime;
    return $body;
  }

  /**
   * Send an email message.
   *
   * @param $message
   *   An associative array containing at least:
   *   - headers: An associative array of (name => value) email headers.
   *   - body: The text/plain or text/html message body.
   *   - MailMIME: The message, parsed into a MailMIME object.
   */
  public function mail(array $message) {
    $eol = variable_get('mail_line_endings', MAIL_LINE_ENDINGS);
    // Ensure that subject is non-null.
    $message += array('subject' => t('(No subject)'));
    // Check for empty recipient.
    if (empty($message['to'])) {
      if (empty($message['headers']['To'])) {
        watchdog(
          'HTMLMailSystem',
          'Cannot send email about %subject without a recipient.',
          array('subject' => $message['subject']),
          WATCHDOG_ERROR
        );
        return FALSE;
      }
      $message['to'] = $message['headers']['To'];
    }
    if (class_exists('MailMIME')) {
      $mime = new MailMIME();
      $to = $mime->encodeHeader('to', $message['to']);
      $subject = $mime->encodeHeader('subject', $message['subject']);
      $txt_headers = $mime->txtHeaders($message['headers']);
    }
    else {
      $to = mime_header_encode($message['to']);
      $subject = mime_header_encode($message['subject']);
      $txt_headers = $this->txtHeaders($message['headers']);
    }
    $body = preg_replace('#(\r\n|\r|\n)#s', $eol, $message['body']);
    // Check for empty body.
    if (empty($body)) {
      watchdog(
        'HTMLMailSystem',
        'Refusing to send a blank email to %recipient about %subject.',
        array('%recipient' => $message['to'], '%subject' => $message['subject']),
        WATCHDOG_WARNING
      );
      return FALSE;
    }
    $extra = NULL;
    if (isset($message['headers']['Return-Path']) && !ini_get('safe_mode')) {
      if (isset($_SERVER['WINDIR']) || strpos($_SERVER['SERVER_SOFTWARE'], 'Win32') !== FALSE) {
        // On Windows, PHP will use the value of sendmail_from for the
        // Return-Path header.
        $old_from = ini_get('sendmail_from');
        ini_set('sendmail_from', $message['headers']['Return-Path']);
      }
      else {
        // On most non-Windows systems, the "-f" option to the sendmail command
        // is used to set the Return-Path.
        $extra = '-f' . $message['headers']['Return-Path'];
      }
    }
    if (is_null($extra)) {
      $result = @mail($to, $subject, $body, $txt_headers);
    }
    else {
      $result = @mail($to, $subject, $body, $txt_headers, $extra);
    }
    if (isset($old_from)) {
      // Set sendmail_from back to its previous value.
      ini_set('sendmail_from', $old_from);
    }
    return $result;
  }

  /**
   * Converts an array of email headers to a text string.
   *
   * @param $headers
   *   An associative array of ('HeaderName' => 'header value') pairs.
   *
   * @return
   *   The concatenated headers as a single string.
   */
  public function txtHeaders(array $headers) {
    $output = array();
    foreach ($headers as $name => $value) {
      if (is_array($value)) {
        foreach ($value as $val) {
          $output[] = "$name: $val";
        }
      }
      else {
        $output[] = "$name: $value";
      }
    }
    return implode("\n", $output);
  }
}