At 8:39 AM 1/31/07, Larry Weldon wrote:
it has been my perception that there are
those who block all dynamic IPs. We should let them speak up if they are
there.
It's difficult to block "all" dynamic IPs, because there is no
authoritative listing of "all" dynamic IPs. But there are some
popular RBL servers which try to list as many as they know about.
The most popular is probably pbl.spamhaus.org, which is also
incorporated into zen.spamhaus.org. Their website seems to indicate
that they list IP ranges which the owning ISPs have identified as
dynamic addresses that should not be hosting MTAs, or which appear to
be dynamic and have been a source of spam. So anybody using
zen.spamhaus.org or pbl.spamhaus.org may be blocking a large number
of dynamic IPs. I'm sure there are less well-known rbls that do the
same. For example, in addition to zen.spamhaus.org, I'm currently
using dhcp.tqmcube.com, which says it lists dynamic ranges and "some
static generic hosts".
Of course, rbls don't really "block" anything, as their owners
constantly point out. They only "list" them. Any blocking is done
by the users of the rbl. And there are different ways that an RBL
can be used. In some cases, it may be used by spamassassin, or
something similar, to raise a spam score if the sending IP is on one
of the "bad" lists. In those cases, the user is not necessarily
"blocking all dynamic IPs". But people like me, who use rblsmtpd
with zen.spamhaus.org in front of qmail-smtpd, are indeed blocking
"many" dynamic IPs, as many as we can.
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