From: J C Lawrence <claw(_at_)kanga(_dot_)nu>
...
I'd go with 2. Most of the thousands of operators of DCC clients seem
to like 20-50. However, some contributors to this mailing list have
insisted that 500 is barely "bulk."
Given that an increasing percentage of spam (its over 15% for me) is
being mailmerged individually to the recipient, I suspect the
description "bulk" for spam at the payload/protocol level is going to be
of short lived use.
The output of mailmerging is bulk because all of the messages are
what has been commonly known as "substantially identical" in
anti-spam circles since before email spam was a problem.
"Substantially identical" is one of those concepts that cannot be pinned
down to something like a ratio of matching bits to total bits. It can
only be approximated by computers and must be interpreted case-by-case
by the legal notion (fiction?) of a reasonable person.
Most spam now includes "hashbusters" that are intended probably to
foil body filters that hope to detect identical copies. It is possible
that those tactics are effective against simplistic body filters, but
they're not effective against anything useful. It's been half a dozen
years since my first body filters ignored salutations like "Dear claw".
Vernon Schryver vjs(_at_)rhyolite(_dot_)com
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