Author: James P. Roberts Date: To: Sandro T. Rafael, exim-users Subject: Re: [Exim] Resolving Problem
> Hello Exim List, >
> I'm receiving this resolve error:
>
> "
> May 5 08:40:16 ms1 exim[31290]: 2003-05-05 08:40:16 19CYhr-000275-00 ==
> info@??? R=dnslookup T=remote_smtp defer (0): SMTP error from
> remote mailer after MAIL FROM:<sysadmin@???> SIZE=2197: host
> mail.dutco.com [64.55.218.57]: 451 4.1.8 Domain of sender address
> sysadmin@??? does not resolve
> "
>
> Any idea what should I do? Our domain (qafac.com.qa) cannot received nor
> send to this domain (dutco.com). Not only dutco.com around 10 domain I
> see having similar problem.
>
> We're maintaining our own DNS and I have both MX and PTR record to my
> mail server (ms1.qafac.com.qa , 212.77.204.5).
>
> I'm using exim-4.12-1
>
> Any hint please? Greatly appreciated.
>
> Thanks.
>
> Sandro T. Rafael
>
Hmm... "dig qafac.com.qa" gave me a "servfail" response, as there is no A
record for it. I then tried "dig ms1.qafac.com.qa" and see the A record for
it. Then I tried "dig qafac.com.qa any" and got the SOA, NS and MX records
for the domain. Finally, I did a "dig -x 212.77.204.5" and find there is no
visible PTR record. All I get is that "212.x.x.x" is delegated to
"ns.ripe.net". Your DNS server may have a PTR record, but it is not properly
delegated to your authority, so the world does not see it.
My best guess is that the domains you are having trouble with are just
checking for an "A" record (the default when not specifying record type),
getting no answer, and not checking deeper. Or, they may be failing you on
the lack of a valid PTR record.
