Is the scenario outlined in my subject (above) possible? I have used the following formula in the past with some success (please don't flame me for the APNIC illustration, it is an example only):
Any Header ==&
matches regexp ==&
I have found that this blocks all mail with [200.xxx.xxx.xxx] in any header. However, owing to the documented SpamAssassin bug (blocking all mail), I have been unable to fully isolate (and therefore fully test) this scenario. To be more specific, all mail is getting blocked, and I'm unsure as to whether my filter is blocking all mail or whether SpamAssassin is.
Has anyone on this forum had success blocking a range of IP addresses (with or without SpamAssassin)? To me, this seems the best way to block 90% of the spam I receive (as I can identify legitimate ranges and block others that are known sources of spam).
I should point out that I only have access to CPanel and SSH for my account.