It is necessary to insert in the title of the letterDisposition-Notification-To: '.$email.' или X-Confirm-Reading-To: '.$email.'
The handler itself ends like this
$headers = 'From: '.$From.' <'.$email.'>'; $headers .= 'MIME-Version: 1.0'; $headers .= 'Content-type: text/html; charset=windows-utf-8'; mail($to, $subject, $message, $headers); Something does not work for me, draw me as it should or offer an alternative version - how to notify that the letter was read?