pop3 proxy

Does anyone know any easy way to manipulate a email message on the fly to only pass the first 200 characters of the message. This application should work as a pop3 proxy server. I need this as an option for my users… they can either log into theregular mail server and receive the entire message, or log in through the pop3 proxy server and receive only part of the message. Any ideas or suggestions would be greatly appreciated.

Thanks
Matthew Rowe