On Mon, Dec 08, 2008 at 09:06:54PM +0900, Masataka Ohta <mohta@xxxxxxxxxxxxxxxxxxxxxxxxxx> wrote a message of 25 lines which said: > If an SMTP or DNS server has multiple addresses, clients are > required, practically (many servers are behind firewalls) or, for > DNS, officially by RFC1035, to try all the IP addresses of the > server, Yes, SMTP requires to try all the IP addresses of the MX. But I thought you said that it was required for a MX to have several addresses, which is quite different. _______________________________________________ Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf