mail filtering ... procmail + php query

hi, after looking at the imap functions...i was wondering how the mail filtering works... afaik procmail does that...but is there any std way / php functions to set the filters? i know the filtering depends on mail server...but if we assume that it is done using procmail... is it somehow possible to write some php code that will take the input from user and generate the .procmailrc file? what problems could occure? any ideas? thanks - Vivek --------------------------------- Do you Yahoo!? New and Improved Yahoo! Mail - Send 10MB messages!