On 3/11/2016 12:54 PM, @lbutlr wrote: > On Fri Mar 11 2016 11:45:31 Viktor Dukhovni <postfix-us...@dukhovni.org> > said: >> >> On Fri, Mar 11, 2016 at 11:38:13AM -0700, @lbutlr wrote: >> >>>> You have some sort of proxy in front of your Postfix server. The >>>> proxy may be blocking Yahoo's servers. >>> >>> That is postscreen, which has a 4 or 5 second delay for new connections >>> however, that connection would be logged, wouldn’t it? >> >> Well, the IP address of the Yahoo host would be logged, yes. They >> may not be willing to wait the 5 seconds. > > Then shouldn’t they generate a DND to the sender?
They would likely treat connection problems as a temporary error, and might not send a delivery notice for several days. But they should eventually send a notice. This problem (postscreen delays legit mail server) is nicely solved by using a dns whitelist such as dnswl.org to bypass postscreen tests for known mail servers... not necessarily "known good" servers, just known to not be a bot. Then your smtpd and content filtering can decide if you want the mail. -- Noel Jones
