PHP邮件只会发送两个收件人

Using the PHP mail() function on a server for a client
When i do:

mail("name@domain.com",$sub,$body,$head);

It fails (returns nothing and is not sent)
But if i do:

mail("name@domain.com,x",$sub,$body,$head);

it works fine

I currently have it set up to this, just so my client can actually do work

 mail("name@domain.com,no-reply@domain.com",$sub,$body,$head);

which is not a great solution, any ideas?

Thanks Andy

If your second senario works fine then in that case you can use

  $receivers = array(
                "name@domain.com",
               "no-reply@domain.com"
              ); 

  foreach ($receivers as $receiver) {
   // to send email one by one to the recipients
   mail("$receiver,x",$sub,$body,$head);

  }

?>