PHP reply-to error - comes with admin email not sender of contact form

Question

I have the below PHP contact form that has a CAPTCHA code to ensure is correct. However, when I reply to the email from the website it puts a random email which i believe is the

Answer 1

Please replace

mail($to, $subject, $body);

with your code

   $headers = "From: $mail\r\n"; 
   $headers .= "Reply-To: $mail\r\n";   

   mail($to, $subject,$body,$headers);