Add another argument and you can specify extra headers like "X-Mailer", "Cc:" or "From:" (sic), for example. If you specify more than one extra header, make sure you separate them with "\r\n" to make sure they work as intended.
Send Emails with Extra Headers in PHP — Example
An example of a simple message with extra headers could look like this:
<?php
$to = "recipient@example.com";
$subject = "Hi!";
$body = "Hi,\n\nHow are you?";
$headers = "From: sender@example.com\r\n" .
"X-Mailer: php";
if (mail($to, $subject, $body, $headers)) {
echo("<p>Message sent!</p>");
} else {
echo("<p>Message delivery failed...</p>");
}
?>
