Claws Mail
Claws Mail is an email client (and news reader), based on GTK+, featuring
Sorting
FindNZB
FindNZB is a great free nzb indexer for Usenet newsgroups. The site offers a free search and download of NZB files. The service is public and open for everyone.
Spotnet
Spotnet is a usenet client that utilizes a peer-to-peer indexing method where users "spot" content on usenet, notifying other clients that the content is there and available.
Spotweb
Spotweb is a decentralized usenet community based on the Spotnet protocol.