You can set the sendmail_from using the following code at line 1 of any page you add Universal Email to.
<?php ini_set('sendmail_from', 'firstname.lastname@example.org'); ?>
Your friends over here at WebAssist! These Dreamweaver extensions will assist you in building unlimited, custom websites.
These out-of-the-box solutions provide you proven, tested applications that can be up and running now. Build a store, a gallery, or a web-based email solution.