hello guys , how can i send my html email through php code , i mean i enter my html codes and then the php code sends it but in form of message not codes ,or any way ,my question is how to send an html email through php code .and also i have a question on how to create my own malling list where people can sign up to it and when i want to contact them i send only one message to all of them without entering all the emails .thanks to all of those who will reply to me .

// To send HTML mail, the Content-type header must be set
$headers = 'MIME-Version: 1.0' . "\r\n";
$headers .= 'Content-type: text/html; charset=iso-8859-1' . "\r\n";
mail("to", "subject", "< b > strong < / b > ", $headers);