Well, you can create a PHP file to contain the variables you want to use and "include" that. example:
file: headers.inc.php
<?php
$from = "Me";
$to = "You";
$fromemail = "me@mydomain.com";
$toemail = "you@yourdomain.com";
$defaultsubject = "Testing";
?>
And in your mailing programs, include the file and use it:
file: email1.php
<?php
include("headers.inc.php");
mail("$to <$toemail>", $defaultsubject, "my message here", "From: $from <$fromemail>");
If this isn't what you're looking for, let us know exactly what headers and information you want to include.
-sridhar
