Textmail filters a mail message or mbox, replacing MS Word, MS Excel,
HTML, RTF, and PDF attachments with the plain text contained therein.
By default, the following attachments are also deleted: image, audio,
video, and MS Windows executables. MS winmail.dat attachments are
replaced by any attachments contained therein, which are then replaced
by text or deleted in the same fashion. Any of these actions can be
suppressed with the command line options. Mail headers can also be
selectively deleted.

WWW: http://raf.org/textmail/