TechRepublic has a writeup of how users of the UNIX-based command-line email client mutt can tweak it to support some of the email triage and management techniques espoused by David Allen’s Getting Things Done system:

“Mutt is extremely powerful, but lacks a little when attempting to implement GTD and the “Inbox Zero” concept. With the aid of a patch that adds support for editing the X-Label header in e-mails (mutt already supports viewing and searching based on the X-Label header), implementing the “Inbox Zero” concept is a few configuration tweaks away.”

Getting things done with mutt [TechRepublic]