Am 22.04.2014 19:02, schrieb Erwan David: > Le 22/04/2014 18:55, Scott Kitterman a écrit : >> On Tuesday, April 22, 2014 18:36:08 Erwan David wrote: >>> Le 22/04/2014 18:29, Tim Smith a écrit : >>>> Just trying to get my head round the error and understand what is >>>> actually happening. >>>> >>>> So to summarize, the delivery.mailspampropection.com domain has 81 A >>>> records which, when queried won't fit into a UDP packet which explains >>>> why Postfix correctly says it can't resolve the hostname. >>>> >>>> Is there some kind of fix I can employ here for this particular >>>> server? Would entries in the /etc/hosts file work? I assume that if I >>>> have "multi on", I can put an entry in for each A record? >>> In that case DNS should switch to TCP or use EDNS, both MUST be >>> available in a modern installation, because DNS answers become larger >>> with new features (IPv6 addresses, DNSSEC, etc.) >> Yes, but all it takes is one firewall that blocks TCP port 53 and the TCP >> fallback fails. Even on the modern internet you have to try to fit in a UDP >> packet if you want reliable service. >> > No, that time is finished. Take a domain with just 2 MXes and an signed DNS > > dig +dnssec MX rail.eu.org -> 1248 bytes
but that doesn't mean someone right in his mind should add 80 ip-addresses to a host and expect this is a good idea, that overhead is *added* to the 1248 bytes and i doubt you get more relieable services with 80 failovers
