> On 26 Mar 2021, at 20:44, FUSTE Emmanuel <emmanuel.fu...@thalesgroup.com> > wrote: > > Le 25/03/2021 à 22:15, Mark Andrews a écrit : >> This is a bug in postfix. Temporary failures in the DNS are not supposed to >> result in permanent failure at the SMTP level. SERVFAIL is not NXDOMAIN. >> > This is not a postfix bug. Temporary failure are perfectly handled by > postfix with a 450 SMTP temporary error, not a 550 permanent error. > > 450 4.7.1 Client host rejected: cannot find your reverse hostname, > [17.179.250.111]; from=<developer_boun...@insideapple.apple.com> > to=<x...@example.com> proto=ESMTP helo=<rn2-msbadger07105.apple.com> > (total: 1)
Fine. I shouldn’t comment before my first cup of tea in the morning. > You should have OS/network configuration problems. Such timeout are > completely unnatural. Timeouts will happen. Networks aren’t perfect. Links can be congested. Links can be noisy. Hosts can be congested. Hosts can be down. There can be routing failures. There are those that configure their DNS such that it requires excessive numbers of lookups to actually resolve an lookup. Then there are those that drop ICMP and fragmented packets breaking legitimate traffic flows. There is a reason there are 400 codes for DNS lookup failures. > Emmanuel. > _______________________________________________ > Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe > from this list > > ISC funds the development of this software with paid support subscriptions. > Contact us at https://www.isc.org/contact/ for more information. > > > bind-users mailing list > bind-users@lists.isc.org > https://lists.isc.org/mailman/listinfo/bind-users -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: ma...@isc.org _______________________________________________ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list ISC funds the development of this software with paid support subscriptions. Contact us at https://www.isc.org/contact/ for more information. bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
