Matt Bernstein wrote:
>
> Anyway I think this kind of paranoia is just silly. It's trivial to forge
> a valid sender address, so why bother checking anything other than a
> syntactically valid domain name?
>
Because, believe it or not, most spammers don't bother. The main server
that I maintain (_NOT_ where I receive L-K) drops at least 20 messages a
day at RCPT TO: time using this very check. Considering that's 50% of
the spam we drop at RCPT TO: time, I'd say it's worth it.
But I do agree, the systems doing the callouts should cache the results
(I'm an Exim 4.10 user as well).
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This archive was generated by hypermail 2b29 : Sat Sep 07 2002 - 22:00:16 EST