Hi all,

This weekend, finally goaded by the spam accumulated over three days'
absence from the office, I decided to upgrade sendmail on our Internet
server to 8.9.1, with its more extensive antispam provisions. One of
those provisions (also available in 8.8.9) is the ability to check the
Mail Abuse Prevention System (MAPS) Realtime Blackhole List (RBL) server
in order to reject mail from known spammers and relay sites.

More than half the spam I get comes not through relay sites, but through
spam generators running on systems connected to the Internet via PPP
connections. I was under the impression that the RBL contained, among
other things, the IP addresses that ISPs assign to dial-up ports, since
legitimate mail relays very rarely use dialup connections. But I've
checked a number of port addresses that I know are on various ISP
terminal servers (UUNet, Mindspring and Earthlink, for example), and none
appear in the RBL. Is there some other server that will allow me to
reject mail from dial-up relays?

-- Bruce

PS. I haven't been able to set up the config files so that sendmail will
reject mail with unresolvable MAIL FROM addresses, but when I figure it
out, that should whack out a fair proportion of the PPP-routed spam.

- B


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Bruce Toback    Tel: (602) 996-8601| My candle burns at both ends;
OPT, Inc.            (800) 858-4507| It will not last the night;
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