HELP! PLEASE! Interfacing EMail to PHP

Please help! Perhaps you have an idea what to do: I want to get information directly from sendmail, like the body of the message and, very important, the receipients address. So if someone sends an email to abcdef@domain.com I want to see who it was sent to. Currently I am using a script that is triggered by an alias in /etc/aliases. Problem here is, I only get the header but no more information. This script isn't intended for one single user but for a whole domain, purpose is for messaging. So I really don't want to create a login for every possible name as I don't know the names before. You have to think of this like a short messaging service where you send a message to 0123456789@domain.com with 0123456789 beeing the phone number of the subscriber. The above mentioned script gets the emails' contents from stdin but fails if e.g. the mail is sent as a blind copy (BCC) or if multiple receipients are listed in the header! Do you have an idea for me? I was thinking about the mailertable, to do something similar as you do when you set up an UUCP account for a whole domain, but I don't know where I can interface. So, any ideas are highly appreciated! Thanks, dk