Is it possible to prevent the following:
From being sent in the email header for added security. I tried to manually add each record to the header information sent by the php mail to show not available to each, however, it just added as a duplicate record while the other was still included.
What script are you using to generate the email?
It is possible that some of those are being added by the mail server after you send the email - Return-Path: certainly would be as it is a mandatory field that is required for security purposes.
The script so far is very basic:
$to = "email@example.com";
$subject = "Test mail";
$message = "Hello! This is a simple email message.";
$from = "firstname.lastname@example.org";
$headers = "From: $from";