The user-friendly, lightweight, and fast email client Latest Release: 3.13.2 (News), on 19 January 2016

The vCalendar plugin

The vCalendar plugin provides groupware features for Claws Mail, namely: The calendars and events are displayed in a list, in the same way that Claws Mail displays your emails.

libcurl is required, http://curl.haxx.se/libcurl/

Here are a few screenshots illustrating the features: