imap_mail()

How do I structure the $additionalHeaders string so that it is useful? Is there a specific order the headers have to be in? How do I delimit multiple headers? I want the from and mailed-by fields to be modified by this variable when mailed from the PHP script. I am getting the server name of my host instead of the domain name of my site. Minor thing because most people probably dont look at headers, but I want it to be professional looking in case someone does. Thank you, Thomas Le "Choose a job you love, and you'll never have to work a day in your life." - Confucius