- an option to "exit on first match", so that after the first failure,
  further checks are skipped, speeding up rejection if there is no
  interest in the specifics of the results.

- follow CNAMEs from rblcheck(). This will let us get at the eventual
  TXT RRs for a domain name.

- timeout option. Should default to no timeout, but apparently there is
  an issue with rblcheck hanging in an offline environment where the
  nameserver in use is located off-site. This would compensate for the
  misconfiguration, and provide a 'quick-fail' mode for people to play
  with.

- (from Aaron Schrab <aaron@schrab.com>) Add a command line option for
  only outputting positive matches. (Notes: add a switch for only
  displaying negative matches as well, and trim down the verbosity in
  each case, so that the "(not) RBL filtered by" text is exempted, since
  it's redundant).

- (from era eriksson <era@iki.fi>) Add a "debug mode", or something
  similar, which reports errors in lookups and reports information about
  what is going on internally to rblcheck.

Send ideas to "emarshal@logic.net".
