On Fri, 21 Sep 2001, Marc Langer wrote:
> On Fri, Sep 21, 2001 at 00:21:13 +0100, Matthew Byng-Maddick wrote:
> > > But how should I reject certain recipient addresses?
> > > I read about receiver_verify, but are feeling uncomfortable with
> > > enabling it. Are there any other possibilities?
> >
> > Can someone explain to me what the problem with enabling receiver_verify is?
> > I can understand in a large site where your mail reception and queue-running
> > are likely to be different processes, but why does it make people
> > "uncomfortable", after all, if the verify fails, then it would fail later
> > and bounce anyway?
>
> I did not fully understand the concept of "receiver_verify" yet.
> Is it sure that there are no more mails rejected than without this
> setting turned on? Especially mails from unknown hosts (without DNS
> entries) must not be rejected.
receiver_verify doesnt veryfy _hosts_, it verifies _email addresses_..
It checks to make sure the domain is valid (eg, has appropriate DNS
entires), and it its a local domain, it can also verify that the
local-part really does exist.
This way, if a host connects and tries to send mail to
fkgfjdgdjfgkdfg@???
(assuming that address isnt valid)
it will be rejeted at SMTP time (and the host trying to send it to you
then is responsible to send the NDR), insead of accepting the message,
_then_ finding out it doesnt exist, and then having the responsibility
to send the NDR itself (possibly to a return address that is fake,
assuming some random spammer was trying to make up addresses at your
site to send to)
>
> Thanks,
> Marc
>
>
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