I've been using the Linux version of MWP for 10+ years, but it no longer functions (SSL issues). So, I installed the Windows version of MWP (6.5.4) to see how it would do (both apps are from the same general time frame, as evidenced by UI).
The basic/essential functions work (spam database, black/white listing, etc.). There are two features which are nice to have, but do not work.
-- Did not find my email application.
-- Cannot minimize to the system tray.
If you need to manage spam, this is the tool.