I went to http://www.iana.org/assignments/ipv4-address-space and grep-ed for APNIC (Asia-Pacific Network Information Center) to get the following list. For the church email site that I support I block wholesale /8 IP address ranges. I assume that for our church we will never get email from an APNIC site.
*snip*
Great, if you intend to never correspond with 202/8, 203/8 and 210/8 you just nuked most of New Zealand and a lot of Australia at the same time.
You might find that being a _tad_ more specific is useful. Believe it or not, theres a lot of legit business conducted between Australasia and the rest of the world...
Mark.
Sorry for replying again, but a quick google revealed this: http://www.okean.com/asianspamblocks.html (note the paragraph reccomending not blocking greater than /16 at a time) And more specifically: http://www.okean.com/china.html This is probably what you're after, if you wish to block only China. Mark.