mboxgrep  0.7.9

About: Scans a mailbox and displays messages matching a basic, extended, or Perl-compatible regular expression. It supports mbox, MH, nnmh, nnml, and maildir folders.
  Fossies Dox: mboxgrep-0.7.9.tar.gz  ("inofficial" and yet experimental doxygen-generated source code documentation)