Re: Interesting spamming tool: a robot to grab e-mail addresses

[Richard Kettlewell <]

Paul Rattray writes:

> Okay, so we all add pages of duff addresses to really screw up his
> nasty spider ... so who gets all the bounces? Unlikely it's the
> originator, unless he/she is intensely stupid.

Depends what return path the spammer sets.  I don't think this creates
a new problem; spam address lists will have many undeliverable
addresses on already, simply due to the rather transient life of many
email addresses.

Once they set return paths to random local parts in one of our
domains.  That was no fun at all - we were bombarded with bounces from
all over the Internet with very little in the way of common
identifying factors.  (Lots of complaints, too, of course.)

We solved that one by identifying all the valid local parts for that
domain and using our spam filters to reject mail to any other
addresses at the SMTP level.  We missed one or two for a couple of
days but we were at least able to continue receiving legitimate mail.

The advantages of pages of undeliverable addresses include:-

 * you tie up the spammer search software when it could be doing
   something useful (for the spammer); this costs them time and money.

 * you increase the ratio of bad:good addresses in their lists.  This
   makes each good address more expensive for them when they are
   sending a spam.

   In the case where they get interrupted halfway through a spam by a
   responsible ISP, they they will have got less far through the whole
   list and presumably therefore less far through the subset of
   deliverable addresses.  So fewer people get spammed.

 * you decrease the value of harvesting the web for addresses.  This
   is useful because it would be a good thing to be able to put one's
   email address on the web without getting spammed as a result.

ttfn/rjk