Windows only: Freeware email application eM Client is a full-featured mail application that comes with a calendar, task manager, and contact manager out of the box. With an easy to navigate graphical user interface that has the familiar feel of Microsoft Outlook and Mozilla Thunderbird, eM Client doesn't really require much of a learning curve. The eM Client team also promises to deliver Google Calendar and Google Contacts synchronization, ActiveSync mobile phone synchronization, and full-fledged CalDev support. Later development promises widget support from Meebo, Facebook, and MySpace. eM Client is a freeware application for Windows only.
eM Client [via Download Squad]