I would like to express my sincere thanks to Gordon for putting together
and maintaining courier-pythonfilter. I use more than just the
greylisting feature and it is a "must have" add-on. I don't know how
Sam and Gordon feel about this, but it would be really nice to have it
included in the main courier release (just like the sample perl
filter). Or maybe, Sam could put it on his courier-mta.org download page.
For all who don't know, here is the download link to courier-pythonfilter.
The "greylist" filter included with pythonfilter is actually newer than
the one on Georg's site. I incorporated most of his improvements, and
merged his secondary scripts into the filter.
That said, the most significant of his improvements, the whitelists,
probably aren't necessary anymore, since pythonfilter has significantly
better whitelisting facilities now than it did when Georg wrote his
version. At some point I'll probably remove the greylist filter's
internal whitelists in favor of the general whitelists.