But if you telnet from an IP that is not registered, you would
be denied. Thus at least eliminating many of the erroneous email servers
out there on the DSL, dial-up and other broadband connections, this has
been tried in the open with such things as MABS RBL, etc by blocking
common spamming IP's and mail servers. But since it is not mandatory, it
falls apart too easily.
"Visionary people, are visionary, partly because of the great many
things they never get to see." - Larry Pingree