Stuff to do to/for the package:

o Add a way of specifying a lifetime maximum number of replies
  for a particular mail source

o Add Makefile stuff to create directory paths if needed (configure option?)

o See about moving man page into internal POD format and extracting
  it during the make

o Add way to tailor --file message (e.g., replace %S with original
  subject, %F with original From:, et cetera); make various timestamps
  available (original sent from header, receipt, autoresponse sent, ...)

  %F (from), %T (to), %S, %U (UTC of response), and %L (localtime of response)
  have been added.  Additional features to be considered later: additional
  timestamps; perhaps %X{header-field-name} substitution?

o Likewise enhance what can be done with the subject line