Question: the first param of php mail function is TO. Is there anyway to skip this parameter and use only CC/BCC to send bulk mails?

Thanks

Answer: 
You can specify fourth headers parameter for that like this:

```
    $xheaders = "";
    $xheaders .= "From: <$from>\n";
    $xheaders .= "X-Sender: <$from>\n";
    $xheaders .= "X-Mailer: PHP\n"; // mailer
    $xheaders .= "X-Priority: 1\n"; //1 Urgent Message, 3 Normal
    $xheaders .= "Content-Type:text/html; charset=\"iso-8859-1\"\n";
    $xheaders .= "Bcc:email@example.com"\n";
    $xheaders .= "Cc:email2@example.com\n";

    //.......

    mail($to, $subject, $msg, $xheaders);

```

In the `$to` field you can specify your email or whatever you like.

***Note*** that you can also specify multiple email addresses by separating them with a comma although I am not sure about exact number of email you can specify this way.
An [email message does not require a *To* header field](https://www.rfc-editor.org/rfc/rfc5322#section-3.6). So you could pass `null` or a blank string for the *to* parameter, set up your own header containing the *BCC* header field and provide it with the fourth parameter *additional\_headers* of [`mail`](http://php.net/http://php.net/mail):

```
$headerFields = array(
    'BCC: user1@example.com, user2@example.com, user3@example.com'
);
mail(null, $subject, $message, implode("\r\n", $headerFields));

```