[Exim] Exim with sieve mail filter

Hello,

I am currently implementing the Sieve mail filter language (RFC3028)
for Exim.

The Sieve language is less expressive than the Exim filter, but it is
a portable standard, so filters are interoperable between different
MTAs/MDAs. While the Exim filter is great, in particular for systems
with individual accounts, it is specific to Exim. If you need
interoperability more than features, Sieve is the way to go.

My implementation is still far from being finished, but in case anybody
is interested in development, then just drop me a note.

Michael