Email server applications
 

I'm running red hat 9 as a server on an ip address through road runner. My question is a multi question question. I need to set up a mail server that will:

a)filter incoming mail from the subject line based on my preferences
b)take the filtered mails and parse data out of the message into a database.

My questions for you all are which cominations of programs will let me do this in the best way? Also should i just use fetchmail or something similiar to get mail off of a different pop 3 server and then do the filtering and parsing. For the parsing would it make sense to use an open source filtering software and edit it to do the parsing upon filter of a valid email? Which open source filtering program (preferrably written in PHP) would be best to do such a thing?
Would a MySQL database be a good selection for the database? I've found an awesome article similiar to what my needs are at Andrew Cooke's website http://www.acooke.org/andrew/writing/email.html . Would these be a good combination of programs to use for my application? My linux background is very limited but I love it so far. Any suggestions would be greatly appreciated.

Thank you,

Jonathan Cobb