CRMME (prounounced "Cream-Me") processes mail from maildirs or mbox (UNIX-style mailboxes) into categories. It provides a simple procmail setup that lets the mail be sorted, and a cron job to learn new messages every night. It is provided as a wrapper around the CRM114 engine written in Python 2.2+ (2.1 with email module is acceptable and tested).
Web applications are code hoarding 2.0
You wrote: "Why not strike out on your own and build a Web-based application that looks as good as a native iPhone app but that isn't beholden to Apple?"
Answer: Because then my users can't fix my bugs or add their own features.
One of the joys of open source and free software is that I can build something that works for me and share it. If someone else wants to customize it or improve it to better suit their needs, they can. As a developer, it frees me from having to solve everyone's problems. As a user, it empowers me to make other people's code more useful to me.
Web applications lack this flexibility.
Just so everyone knows, the Freshmeat page says that this program is GPL'd, but in fact that's only true for the source download listed.
The binaries are covered under a different, non-free-software (but free-of-cost) license. You can read about the details at by looking for "The VirtualBox binaries are available free of charge for personal and evaluation use. By downloading from the below links, you agree to the terms and conditions set forth by the VirtualBox Personal Use and Evaluation License (PUEL) (http://www.virtualbox.org/wiki/VirtualBox_PUEL)." at http://www.virtualbox.org/wiki/Downloads (http://www.virtualbox.org/wiki/Downloads).