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. Scott K
