On Thu, 23 May 2002, Riccardo Baldanzi wrote:
> Sorry, my fault....i've activated firewall logging and i saw that exim was
> calling back host in DNS MX query.
> Unfortunately, in my case, that host was permanently down and so exim is
> temporarily unable to verify sender and neither the receiver or the sender
> received any error (why?).
Well, if you have enabled callbacks, and you verify the sender address,
and their MX host is permanently shut down, it wont be able to verify
the senders address via callback.
The sender will also be unable to receive any non-delivery notice, if
their MX host is permanently shut down. If you dont have any reason to
beleive otherwise, it was probably a spammers domain, they spammed from
somewhere other than their MX host (dialups, open relay, ...), and the
provider hosting their mail found out and shut them down.
>
> I must test more carefully before posting.
>
> Riccardo
>
> At 10.03 23/05/2002, you wrote:
> >On Wed, 22 May 2002, Riccardo Baldanzi wrote:
> >
> > > 2002-05-20 17:54:22 179pUM-0000jc-00 rejected from
> > > (mail5.cs.interbusiness.it) [151.99.250.40]: temporarily unable to verify
> > > sender address <user1@???> (try later)
> >
> > > Why exim is calling back the sending host? It should callback host in DNS
> > > MX query....
> >
> >It should call back to the host that Exim gets from its routers. That
> >*may* be from an MX, but it depends on how your routers are configured.
> >What is the output from "exim -bt user1@???" ?
> >
> >However, that log line doesn't show that a callback failed. All it says
> >is that it couldn't verify that address. This could be for several
> >reasons - e.g. it couldn't look up the MX records. 151.99.250.40 is the
> >*sending* host, not the callback host.
> >
> >
> >--
> >Philip Hazel University of Cambridge Computing Service,
> >ph10@??? Cambridge, England. Phone: +44 1223 334714.
>
>
> --
>
> ## List details at http://www.exim.org/mailman/listinfo/exim-users Exim details at http://www.exim.org/ ##
>
>
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