PGP posting validation

[Matthew J Ghio]

DrZaphod says:

	Ah ha!  Another facet of a LIST run authentication system
	[Cypherpunks Run Authentication System - CRASs?]
	may be to allow users to mail THE LIST and ask their mail
	to be filtered so they don't have to pay for msgs they don't
	want.  THIS IS DANGEROUS because a forger could mail in
	such a request.. to patch this, THE LIST could mail out a
	weekly msg -- a compiled list of which msgs got thru, and
	which were filtered, and why. 

Or, you could do what is done on the extropians list:  Every time a
filter/block or other command is received, the list software sends back
a note confirming it.  It would make it pretty obvious if someone was
spoofing fake filtering commands.