Subject: Re: [Asrg] Fwd: Returned mail: see transcript for details

From: wayne <[email-masked]>
Date: 01 Apr 2003 08:46:40 -0600

In <[email-masked]> Vernon Schryver <[email-masked]> writes:

> > From: wayne <[email-masked]>
> >
> > Ah.  What I meant is that I can check to see if someone is in the
> > SPEWS DNSBL, but I can't see if a given email will be rejected as spam
> > by a given content filter. 
> 
> Again, given an SMTP server and a test message, simply send the test
> message to an invalid mailbox at that server.  If the bounce you get
> from the remote server or your own SMTP client says "user unknown,"
> then chances that are the remote SMTP server will not have filtered
> the same message if sent to a valid address.

Uh, I don't see how you can come to that conclusion.  Most MTAs will
reject the invalid mailbox at the SMTP RCTP TO time and the actual
mail message won't even be delivered the receiving MTA.

>                                  The same applies to DNS blacklists,
> because MTAs can and do lie about how they use DNS blacklists [...]

The point I was making is that it is easier for people to complain
about DNSBLs because they are easier to publicly show that they are
listed on the BL.  This means that the number of public rants against
DNSBLs is misleading compared with other anti-spam systems that aren't
as transparent.

-wayne

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---

From: Vernon Schryver <[email-masked]>
Date: Tue, 1 Apr 2003 08:37:18 -0700 (MST)

> Uh, I don't see how you can come to that conclusion.

via brain fart.

>                                                       Most MTAs will

Good point.  So I guess you have to send to a known good address and
hope the recipient doesn't mind.

> ...

That's true.  It's also true that public rants about blocking is skewed
by DNS blacklists that tell listees to rant in public to contact the
list administrators.

I tend to discount and ignore the public rants along with the bragging
about "kill counts."  The serious spammers never seem to rant in
public.  They only spam and sometimes file court papers.

Vernon Schryver    [email-masked]
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