On Wed, 10 Dec 1997, John Henders wrote:
> I just noticed that if an address is rewritten with sender_verify_fixup,
> then there is no way to match it against your reject database. I guess
> this is because the lookup on sender_reject is done at the MAIL FROM
> stage and a rewrite is done after the DATA is accepted as you need the
> Reply-to to do the rewrite. Is there any way we could work around this?
> I'm seeing spammers get around our filters by using a random address in
> mail from and their real blocked address in reply to. I've turned off
> sender_verify_fixup as that seems to be the only solution.
I don't personally think sender_verify_fixup is a good idea!
However, I have made a note to look into the possibility of checking the
rewritten address against any blocking lists. Unfortunately, as you
point out, all this happens after the DATA has been received, so
rejections may not stop the remote host trying again with the same
message.
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Philip Hazel University Computing Service,
ph10@??? New Museums Site, Cambridge CB2 3QG,
P.Hazel@??? England. Phone: +44 1223 334714
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