How to send email to multiple recipients using drupal_mail?

Question

I am using drupal_mail to send email,

$to = '[email protected]';
drupal_mail('$module_name', $key, $to, language_default(), $params = array('username' => 'Tanvir'), $from = NULL, $send = TRUE);

I want to send email to multiple email addresses at once. Should I be doing this?

$to  = array('[email protected]', '[email protected]', '[email protected]',);
drupal_mail('$module_name', $key, $to, language_default(), $params = array('username' => 'Tanvir'), $from = NULL, $send = TRUE);

Answer 1

The to-parameter to drupal_mail is a string, not an array. But you can have as many receipent as you like in the the e-mails "to" string, provided they're separated by commas.

So to send the same mail to multiple recipients, do the following:

$to  = '[email protected],[email protected],[email protected]';
drupal_mail('$module_name', $key, $to, language_default(), $params = array('username' => 'Tanvir'), $from = NULL, $send = TRUE);

Se also API documentation for drupal_mail

Answer 2

Use hook_mail to send multiple receipients by passing:

$params = array();
$params['cc'][] = '[email protected]'
drupal_mail('$module_name', 'custom_key', $to, language_default(), $params = array('username' => 'Tanvir'), $from = NULL, $send = TRUE);


//hook will be the module name

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

  if ($key == 'custom_key') {
    $message['headers']['cc'] = $params['cc'];
    //.
    //.
    //.
    //.
  }    
}

Answer 3

According to PHP doc you can send only one letter via one call of function drupal_mail. So, you should use cycle. Example

$to  = array('[email protected]', '[email protected]', '[email protected]',);
foreach ($to as $email) {
  drupal_mail('$module_name', $key, $email, language_default(), $params = array('username' => 'Tanvir'), $from = NULL, $send = TRUE);
}

Answer 4

If you read drupal_mail function documentation then you'd see '$to' param accepts string not an array in certain formats like:

1. [email protected]
2. [email protected], [email protected]
3. User
4. User , Another User

So, we can easily convert your $to array into required format using implode function and hence you'll be to send email to multiple recipients in one go. Here's the code:

$to  = array('[email protected]', '[email protected]', '[email protected]',);

//To change array('[email protected]', '[email protected]', '[email protected]',)  -> '[email protected], [email protected], [email protected]' use implode

$to_str = implode(",", $to);

drupal_mail('$module_name', $key, $to_str, language_default(), $params = array('username' => 'Tanvir'), $from = NULL, $send = TRUE);