* git
* SpamAssassin (spamc/spamd)
* MTA - postfix is recommended
-* lynx (for converting HTML messages to text)
* Perl and several modules: (Debian package name)
- Date::Parse libtimedate-perl
- - Email::Filter libemail-filter-perl
- Email::MIME libemail-mime-perl
- Email::MIME::ContentType libemail-mime-contenttype-perl
- Encode::MIME::Header perl