I used to get problems with sending PHP emails, AOL just wouldnt receive them. I then turned to Coldfusion to solve this..
My entire website is written in PHP but I use a .CFM page to send the EMAIL.
THE .cfm page is an inbetween page from submitform.php to submitedok.php .
My googlemail account receives the email but AOL doesnt even send this email to spam.. God knows where its going!