How to use phpmailer to send email to multiple addresses one by one?

I want a foreach loop to send email to multiple addresses each time I run the PHP code:

$id = "a@a.com
    b@c.com
    d@e.com";

$new = explode("\n", $id);

foreach ($new as $addr) {
    $mail->addAddress($addr);
}

if (!$mail->send()) {
    echo "Mailer Error: " . $mail->ErrorInfo;
} else {
    echo "Message sent!";
}

But it put all the email addresses in to field and then sends the email.

So when someone get the email, he can see all the email addressees in the to field.

I want a code to send emails one by one.

The problem you have is that you're actually adding multiple recipient addAddress() before actually sending the email.

So, after your loop...

$mail->addAddress('a@a.com');    // Add a recipient
$mail->addAddress('b@c.com');    // Add a another recipient
$mail->addAddress('d@e.com');    // Add a another recipient

the TO address is now a@a.com, b@c.com, d@e.com
And then... you're sending the email to all of them.

To send the email one by one I would initialize the mail object completely inside the loop.
(or call another function passing the address as an argument).