Re: [exim] Re: using rfc-ignorant as a whitelist!?!?!?

On Mon, 27 Jun 2005, Mike Zanker wrote:

> Yes, Postfix has an option "unknown_local_recipient_reject_code"
> which is set to 550 by default but the comments in the main
> configuration file suggest starting with 450 until happy with other
> settings.

Thanks,

It's curious that there had been so many from .br domains that I had
supposed it to be some kind of local custom - analogous to the way
that many Chinese MTAs seem to reject "mail from:<>" out of hand.
But I hadn't done any kind of statistics - this was just based on
seeing what was flying past our mailer.

The most recent example seen here was planetaeducacao.com.br, here's a
test to confirm it:

RCPT to spoofuser was refused:
450 <spoofuser@???>:
User unknown in local recipient table

And here's their SMTP banner:

220 plmail.planetaeducacao.com.br ESMTP Planeta Educação

Not sure how much that tells us, though.

Similar response from brasilux.com.br:

450 <spoofuser@???>: Recipient address rejected: User
unknown in local recipient table

where the banner is:

220 serverlinux.brasilux.com.br ESMTP "Version not Available"


The sender addresses in question may very well be faked, of course:
I'm not accusing these particular domains of being spam sources as
such - merely of responding in an unhelpful way. And these are only
two examples from quite a list that I collected over time.