Complex sentence: The responsible IETF Area Director agreed to sponsor the publication of some of the unpublished MARID decisions as IETF experiments; these happened in 2005, as both "classic" pre-MARID SPF and Sender ID were approved as experimental RFCs.
Split into simpler sentences: The responsible IETF Area Director agreed to "sponsor" the publication of some MARID fallout as IETF experiments, this happened in 2005. Both "classic" pre-MARID SPF and Sender ID were approved as experimental RFCs.