Grepmail

	Gzip, bzip2, tzip support
	Piped input supported (compressed or not)
	Supports complex dates like "between Jan 15, 1999 and 5 weeks ago"
	Can ignore non-text MIME attachments
	Can search only the header or only the body of an email
	Can recurse subdirectories
	Automatically optimizes for speed vs. flexibility when searching based on date constraints.

	Download most recent version (5.3033)
	Change log
	Get the code via CVS
	See the todo list.
	Register to be notified of updates
	Join the users and developers mailing list
	Visit the public chat forums: Open Discussion, Help, Developers
	Report a bug, or submit a patch
	SourceForge project page for grepmail

grepmail has been integrated with several mail readers:

• pine: grepine, by Cristin Pietsch. Automatically sends the output of grepmail to pine.
• mutt: grepm, by Moritz Barsnick. Automatically sends the output of grepmail to mutt.
• VM: vm-grepmail.el, by Robert Fenk.
• Gnus: nnir-grepmail.el, by Nevin Kapur. This is an add-on for nnir.el. I'll update this link if the add-on is incorporated into nnir.el directly.

Also check out Jeremy Malcolm's gtkgrepmail, a graphical front-end for grepmail.