[Exim] Database + Mysql

Please excuse me if there is a easy answer to this
question, im new
at this program :)

How would i go about setting up exim with a mysql
database? I have set up my database and uncommented
the LOOKUP lines in the exim config file.

What i want to be able to do is to get the body of any
incoming messages and then stick them into a database.

I only want to store messages of length 255 chars so
that'd work with mysql

Thanks in advance.