First, you don’t want to suppress errors, which is what the @ does.That will also tell you if it was sent, which you might want to know about.
Like I said previously, I am not a fan of the mail function and use MailGun, but to answer your question, you need to add headers to the argument list - OR - loop through the list and send them individually.
$headers[] = 'Bcc: [email protected]';
However, you still have tidying up to do. Your form code shouldn’t list the email inputs individually. They should be something like this,
<input type="email" name="email[]">
That will give you an array of emails. Then you just need to either compress them like this:
$emails = implode('; ', $_POST['email']);
// using them to send blindly would look like this
if(mail(null, $tsubject, $ttext, "FROM: $_POST[youremail]", $headers)) {
// sent successfully
} else {
// sending failed to send
}
Or send them in a loop
foreach($_POST['email'] as $email) {
if(mail($email, $tsubject, $ttext, "FROM: $_POST[youremail]")) {
// sent successfully
} else {
// sending failed to send
}
}