Author: David Woodhouse Date: To: ROGERS Richard CC: Peter Velan, Exim Users Mailing List Subject: Re: [exim] Blocking non-authenticated senders
On Tue, 2007-02-20 at 17:12 +0000, ROGERS Richard wrote: > On the other hand, the vast majority of messages that have identical
> envelope FROM and RCPT addresses are spam (here at least). So IF you
> provide your users with a per-user whitelist system then you could
> consider blocking that class of messages - that way you have a cheap and
> effective check that your users can easily bypass if they need to.
>
> You may also want to consider blocking
> nonexistent-local-part@???, but I think David is right, it's
> probably wise to steer away from a "blanket" block on
> any-address@??? !
It's not just "nonexistent-local-part". It's any local part which it
never validly used in MAIL FROM:<...>, even if it does actually exist.
In my case, that includes the local-part 'dwmw2', because all mail is
sent with an automatically generated reverse-path instead. You'll never
see a genuine 'MAIL FROM:<dwmw2@???>', and anyone bothering
with sender verification callouts will be rejecting the fakes.
