On Tue, 2004-09-14 at 15:27 +0100, Philip Hazel wrote:
> On Tue, 14 Sep 2004, Sean Hoggard wrote:
>
> > Most spam messages have false addresses anyway,
>
> Not true. Used to be true. Then people started checking.
We're into a syntactical battle here.
Spam used to just have made up sender addresses on. Then people started
checking address validity and that spam got rejected at SMTP time.
The spam had valid but forged addresses (leading to the delightful Joe-
Job bounce storms) (there may be an intermediate stage of spam having
valid (forged) domains and made up local_parts). CBV tended to kill
that one.
Now spam is coming from valid (SPF valid) sender addresses that the
spammer owns, and throws away after use - although there is probably no
working reverse path. The address is "valid" but quite likely "false"
in the sense Sean meant as no one will ever get the bounce.
http://www.theregister.co.uk/2004/09/03/email_authentication_spam/
Unfortunately valid SPF isn't quite a good enough indicator to reject
mail on...
Nigel.
--
[ Nigel Metheringham Nigel.Metheringham@??? ]
[ - Comments in this message are my own and not ITO opinion/policy - ]