Ximian Evolution[tm] is the premier personal and workgroup information
management solution for UNIX.  Evolution seamlessly integrates email,
calendaring, meeting scheduling, contact management and online task lists
in one powerful, fast, and easy to use application.  It also delivers a
comprehensive set of features that help keep work organized and projects
on track.  The unique Ximian vFolders[tm] are virtual folders used to
create and save powerful contextual views of email messages.

WWW: https://wiki.gnome.org/Apps/Evolution