> As part of an anti-spam system I'm working on, it might turn out to be
> very helpful to know the envelope sender addresses used by various
> mailing lists, i.e. many/most/all of the legitimate opt-in mailing
> lists in existance. ...
> But Jeffrey's message would seem to indicate that doing this, en mass,
> for lots of mailing lists, might well raise hackles in many quarters.
Of course it would. It's exactly the kind of intrusive probing and scanning
that's gotten you into trouble so often in the past.
Lots of lists are set so that the list owner manually vets each subscription
request, and list owners are unlikely to enjoy being mailbombed by your
subscribe-bot. The ones that do permit automated subscription log all of the
requests, and they're not going to be pleased to see a lot of mystery traffic
from you either.
It's not even very useful. I believe you'll find that there are only maybe
20 list management packages that are in wide use, and even with the range of
MTAs that people use, you can probably come up with under a hundred patterns
that would identify the lists as well as anything would. Also remember that
many lists use per-recipient sender addresses to help automate bounce
processing, so you'd need to do pattern matching even if you tried to collect
a sender address from every single list around.
John Levine, johnl @
com, Primary Perpetrator of "The Internet for Dummies",
Information Superhighwayman wanna-be, http://iecc.com/johnl, Sewer Commissioner
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