Send Multi part Mail in Drupal 7/8¶

Resources¶

Why Multi-Part Email is Important¶

Most of Emails reported as spam and not deliver to client mail, So there was steps you must follow when you send email to limit spam score and the Preference is use multipart/alternative as content type then Separate your mail body in two content types first one is text/plain this is for Client Applications that’s not Support or Cannot Parse HTML tags and the other is text/html for Client Applications that’s support HTML but the priority for text/html if Client Application able to parse HTML tags .

Implementation in Drupal 7¶

drupal_mail('module_name', 'TEST_SMTP', 'client@example.com', 'en' ,['key' => 'value']);

-  Implementation in drupal 7 like drupal 8 , the only difference
   that drupal 7 using ``drupal_mail`` function and in drupal 8 you
   must get mail manager service to send mails .

Implementation in Drupal 8¶

class DefaultController implements ContainerAwareInterface {

    /** @var MailManager */
    protected $mailManager;

    /* dependcy injection */
    public function setContainer(ContainerInterface $container = null) {
        $this->mailManager = $container->get('plugin.manager.mail');
    }

    public function testSendMailAction() {
        $this->mailManager->mail('module_name', 'TEST_SMTP', 'client@example.com', 'en' ,['key' => 'value']);
        return [
            '#type' => 'markup',
            '#markup' => 'This Page In development '
        ];
    }

}

``class DefaultController implements ContainerAwareInterface`` \*
Implementing ContainerAwareInterface to inject mail service into
Controller, also you can extend ControllerBase if you need but in
this case we don't\` need to extend BaseController class.

``$this->mailManager = $container->get('plugin.manager.mail');`` \*
this line to get mail manager service

``$this->mailManager->mail('module_name', 'TEST_SMTP', 'client@example.com', 'en');``
\* It's very simple to use, First parameter is your module name to
call hook\_mail , Second parameter is the key that use in hook\_mail
to specify content , Third parameter is client mail and you can add
more than one email by using comma separator (,) between emails ,
'en' this is the encode of email ,and last parameter for sending
parameters as associative array that will receive in hook\_mail

Now open your module_name.module file and implement hook_mail function

function module_name_mail($key, &$message, $params) {

  $message['from'] = \Drupal::config('system.site')->get('mail');
  $Plainttext = "Plaint Text Part";
  $HTMLpart = "<h1>HTML Part</h1>";
  switch($key)
  {
    case 'TEST_SMTP' :
      $message['subject'] = 'Test Email from Opensource Wiki';
      $message['headers'] = array(
        'MIME-Version' => '1.0',
        'Content-Type' => "multipart/alternative",
        'Content-Transfer-Encoding' => '8Bit',
        'X-Mailer' => 'Drupal'
      );
      $message['body'][] = "\r\n--\r\n";
      $message['body'][] = 'Content-Type: text/plain; charset=utf-8;';
      $message['body'][] = "$Plainttext";
      $message['body'][] = "\r\n--\r\n";
      $message['body'][] = "Content-Type: text/html; charset=utf-8;";
      $message['body'][] = "$HTMLpart";
      $message['body'][] = "\r\n-- --\r\n";
      break;
  }

}

This is the important part in your code to send mail .

$message['from'] = \Drupal::config('system.site')->get('mail'); * To specify the sender email address by this Code and we always use system site email (you can change this to any email as you like)

$message['subject'] = 'Test Email from Opensource Wiki'; * set subject of email

$message['headers'] = array( 'MIME-Version' => '1.0', 'Content-Type' => "multipart/alternative", 'Content-Transfer-Encoding' => '8Bit', 'X-Mailer' => 'Drupal' ); * set headers of email and make sure you are set content type as multipart/alternative

['body'][] = "\r\n--\r\n"; $message['body'][] = 'Content-Type: text/plain; charset=utf-8;'; $message['body'][] = "$Plainttext"; $message['body'][] = "\r\n--\r\n"; $message['body'][] = "Content-Type: text/html; charset=utf-8;"; $message['body'][] = "$HTMLpart"; $message['body'][] = "\r\n-- --\r\n"; * You must add boundary code before and after each content type but it is not required to do that if you are using PHP_Mailer Library this part to set plain text and HTML tags (syntax is very important check Resources)

$message['params']['attachments'][] = array( 'filecontent' => file_get_contents(PATH_OF_FILE), 'filename' => 'file_name.extention', 'filemime' => 'application/type', ); * To attach files use this code

NOTES:

Some library or PHP native needs to encode your file after using file_get_contents function , check your library requirements.
Email Client Applications use base64_decode to decode attachment as default .
Download and enable SMTP Module then enter your SMTP configuration from http://host/config/system/smtp .
Change mailing system by this command drush cset system.mail interface.default SMTPMailSystem .