Pan-0.14.2 is an GTK2 based newsreader program.
KNode is a Qt based newsreader program from kdenetwork-3.1.4.
KMail is a Qt based mail client from kdenetwork-3.1.4.
Balsa-2.0.14 is an GTK2 based mail client.
Mozilla-1.4 includes both a mail client and newsreader in its installation along with notes for installing Mozilla Thunderbird, a mail/news client based on the Mozilla code base.
Evolution-1.4.4 includes an GTK2 based mail client.