Archiveopteryx is an email archiving and query system, making use of postgresql for message storage, search and categorization and available under BSD license.
Created attachment 256105 [details] Initial ebuild for the package in question.
Created attachment 256107 [details] Pathes and variables patch for building
Created attachment 256109 [details] Initial init.d script for the archiver
One additional comment: the package ships with both a "real" Jamfile and an autogenerated Makefile, provided for convenience. I chose to rely on ftjam for building, to obtain more consistent results in case distro patches would have to be applied.