This is Grendel -- a Java mail/news client.

The grendel.storage package is is where we implement most (all?) of the
javamail API.  Private to this package are any details about particular
protocol implementations.  All the differences between NNTP, IMAP, POP,
etc. are packaged away in here and hidden.  This also implements the RCFdata
interfaces; that is, this is the stuff that supports RDF queries.

See http://www.mozilla.org/projects/grendel/index.html for more info.