The following extra packages may be required on your platform, either to satisfy dependencies or just to complete the filter chain used in some test setup described in papers or on mailing lists. Besides standard packages expected to be found on any Linux/Unix system, that is.
md5: e72e5c94008865cf720992a0b25d6e89) of Ville Laurikari's TRE engine. Check his homepage at http://laurikari.net/tre for latest version. CRM114 can be compiled against other RE engines, eg GNU's which may be already available on your system, but TRE has several key features so that it's become the
standardRE for CRM114.
normalizer(to convert obfuscated MIME stuff into readable and tokenizeable text) to be a good thing. There are many around, but we recommend normalizemime. Among other things, it's actively maintained by Jaakko Hyvätti to deal with the latest kinks known by spammers. You do not need normalizemime, but if you want a MIME normalizer, this one is a good one.