Complete mail header

Question

I need a set of mail headers to attach to my mail() function in PHP. I send emails with HTML in them, and sometimes services like Yahoo Mail block them. Therefore I need to make sure that I am at least providing the right headers.

My code:

// 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";  // Additional headers $headers .= 'From: MyCompany <[email protected]>' . "\r\n";   

Is there anything else I should add?

Answer 1

    $headers  = "From: testsite <[email protected]>\n";     $headers .= "Cc: testsite <[email protected]>\n";      $headers .= "X-Sender: testsite <[email protected]>\n";     $headers .= 'X-Mailer: PHP/' . phpversion();     $headers .= "X-Priority: 1\n"; // Urgent message!     $headers .= "Return-Path: [email protected]\n"; // Return path for errors     $headers .= "MIME-Version: 1.0\r\n";     $headers .= "Content-Type: text/html; charset=iso-8859-1\n"; 

Answer 2

Most MUA's insert a lot of extra headers; however, here is sort of the bare minimum you can expect.

To:  Subject: Date:  MIME-Version: Content-type:  

If you using HTML, then you should probably be using multipart messages--but it's not strictly necessary.