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Re: Which Spam Block List to use for a network?

On Wed, 23 Jun 2004 18:23, Blu <blu@daga.cl> wrote:
> Well yes. Maybe I oversimplified. What I do is a callback to the MX of
> the envelope sender to see if it accepts mail to him/her. If not, the
> mail is rejected with an explicative 550.

You aren't the only one who does that.  I have found one other person who does 
that and who happens to have their mail server in an address range that's 
black-listed.  So when I sent mail to them their mail server made a call-back 
to mine, my server rejected that and their mail server then generated a 55x 
code that tried to summarise the code from mine.  Then my mail server took 
that and made it into a bounce message.

The resulting message was something that I could not decipher even though I 
have 10 years of experience running Internet mail servers!  All I could do 
was post a message to a mailing list I knew the person was subscribed to and 
inform them that their server was borked in some unknown way.

What would the average Internet user do in such a situation?

The typical 55x message about a DNSBL rejection is clear enough that most 
people can get some idea of what to do (IE phone the person, use a different 
mail server, etc).

The call-back idea may be good if you have a domain totally full of clueless 
morons who only receive mail from skilled administrators who have experience 
in dealing with call-back systems.  But if you have average people exchanging 
email with other average people (the common case) then it will make things 
worse not better.

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