On Thu, Feb 24, 2011 at 8:29 AM, Wietse Venema <wie...@porcupine.org> wrote: > While looking at the logs, I noticed that I had found a solution > for the mail delivery delay after a deep protocol test. The solution > is so simple that it should have been obvious long ago: > > - Client connects to primary MX address, goes through the deep > protocol tests, passes the tests, gets a 4XX response from > postscreen, and hangs up. > > - Client immediately connects to the backup MX address, and delivers > mail immediately, because it is already whitelisted. Thus the > delay after "deep protocol test" is eliminated. >
Wietse, Could a similar outcome work if you have MX set something like this: 10 MX smtp-in-1.mydomain.com 20 MX smtp-in-2.mydomain.com With both smtp-in1.mydomain.com and smtp-in-2.mydomain.com resolving to the same IP? Are you aware if mail clients will discard the retry on the backup host if it resolves to the same IP, or is that taboo in the SMTP RFC? - N
