On Tue, Oct 23, 2001 at 06:45:16PM +0001, Ken Jackson wrote:
>So the empty <> is nothing to do with 'spam' and is actually a desired thing
>to have? Or am I reading it incorrectly?
The sequence goes:
Spammer sends message to non-existent user at your domain.
Your mailserver tries to send back "that user doesn't exist", with the
correct MAIL FROM: <>.
This fails, because the spam doesn't contain a valid return address.
Thus a delivery failure report has itself failed; so you end up with
a frozen message from <>.
Roger