Piping new email to a PHP file

Hi, I'm sorry if this has been asked many times before but how do I pipe new email to a file instead of to a mailbox? I tried adding an alias to a file, but it bounced and said 'Can't write output', then I tried to pipe it to a program (the php interpreter) like this "|php /home/php-script.php" and that didn't work either. Basically, what I'm trying to achieve is to have all new email sent to a certain address parsed and inserted into a database. I want to do this with PHP, which I'm comfortable with, but I don't know where to start.