El jue, 3 dic 2020 a las 22:23, Viktor Dukhovni (<postfix-us...@dukhovni.org>) escribió:
> > On Dec 3, 2020, at 7:28 PM, Sergio Belkin <seb...@gmail.com> wrote: > > > > Thanks Bastian, I had to obfuscate the domain name due to privacy issues > :-/ > > But I told to Wietse, that domain name has a MX record with an 'A' > record associated, but lacks of 'AAAA' record. > > What is weird for me is that it happens sometimes not always with that > domain... > > Even after Wietse and I prowled around in all the > dark places in the code, we still failed to find > a plausible way for a soft error in IPv4 lookups > to fail to suppress a hard NODATA for IPv6 lookups. > > The only possible explanations are: > > - Your resolver erroneously reported NODATA for IPv4 > - The authoritative nameservers reported NODATA for IPv4 > - Neither of us was able to spot a subtle bug > > To distinguish between these, it would be helpful if you > set: > > debug_peer_list = another-example-com.mail.protection.outlook.com > debug_peer_level = 1 > > and if/when the problem happens again, either posted a sanitised > log (with the guilty domain name obscured as appropriate) to the > list, or sent a copy to just me and Wietse off list. > > I'd like to see the actual queries and responses logged by the > Postfix SMTP delivery agent. > > -- > Viktor. > > Thanks Viktor and Wietse, up to now the error didn't happen again. Some information about my software that may be useful: libc-2.17-260.el7_6.4.x86_64 glibc-2.17-260.el7_6.4.i686 dnsmasq-2.76-7.el7.x86_64 -- -- Sergio Belkin LPIC-2 Certified - http://www.lpi.org