i know that this is not freeware, but the application, stores it's settings in ini files and can the last version look pretty neat with multiple news servers support and (but I not checked it) multiple e-mail accounts too, there is possibility to use for free a less featured non registered version which is freeware
i think it should be on a list here
Portable Thunderbird seems to be the most popular choice...
Rob Loach [Website] [Projects]