Send HTML email from my module

Question

I have a problem while sending a HTML email through my module, Here is my code below:

.install file

function invite_an_user_enable() {
  $current = variable_get('mail_system', array('default-system' => 'DefaultMailSystem'));
  $addition = array('invite_an_user' => 'invite_an_userMailSystem');
  variable_set('mail_system', array_merge($current, $addition));
}

function invite_an_user_disable() {
  $mail_system = variable_get('mail_system', array('default-system' => 'DefaultMailSystem'));
  unset($mail_system['invite_an_user']);
  variable_set('mail_system', $mail_system);
}

and here is the .module file:

class invite_an_userMailSystem extends DefaultMailSystem {
  public function format(array $message) {
    $message['body'] = implode("\n\n", $message['body']);
    $message['body'] = drupal_wrap_mail($message['body']);
    return $message;
  }
}

Here is the email that I got:

<p>Hi <strong>[email protected]</strong>,&nbsp;</p>

<p>Your friend <strong>[email protected]</strong>, invited you in <strong>My Site Name</strong>. Please cleck on the link to accept the invitation below:</p>

<p>http://something.com/referral/3139323e</p>

<p>&nbsp;</p>

<p>Thanks,<br />
My Site</p>

Now the problem is that, when I received the email I can see all the tags in my email. And the header of the email is

MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed; delsp=yes
Content-Transfer-Encoding: 8Bit
X-Mailer: Drupal

I believe this should be text/html rather than text/plain. Am I doing something wrong? Is there any different method to send HTML mail? Feel free to ask any questions.

Answer 1

Solved that. I added a line on my code i.e $message['headers']['Content-Type'] = 'text/html; charset=UTF-8;'

class invite_an_userMailSystem extends DefaultMailSystem {
  public function format(array $message) {
    $message['headers']['Content-Type'] = 'text/html; charset=UTF-8;';
    $message['body'] = implode("\n\n", $message['body']);
    $message['body'] = drupal_wrap_mail($message['body']);
    return $message;
  }
}

This is now working for me.. Yeppi :)

Answer 2

Add your custom module hook_mail:

/**
 * Implements hook_mail().
 */
custom_module_mail($key, &$message, $params) {

    $message['headers']['Content-Type'] = 'text/html; charset=UTF-8;';
}

Make the "drupal_mail" call as follows:

drupal_mail('custom_module', 'unique_key_first_arg', $to, user_preferred_language($currentUser), ['body' => 'content goes here', 'subject' => 'SUBJECT LINE goes here'], $from, TRUE);