Hi Brandon, Does GMail publish a list of its outbound hosts/ranges some place to enable us to whitelist?
Kind regards, Mike On 25 February 2016 at 23:30, Brandon Long via mailop <[email protected]> wrote: > I should point out that "typical" greylisting doesn't work well with > Gmail, since there is no guarantee that the retries will be performed from > the same IP address... in fact, the chances are really high that it's from > a different one. > > By typical, I mean based on any tuple which includes IP. > > We will try multiple hosts in preference order if we fail connections to > earlier hosts or if the hosts return a 4xx banner. We do also "learn" down > hosts, and will skip them without trying for limited periods of time (given > the mechanism there, it probably is only really used for fairly high volume > domains). > > I can only imagine how greylisting would actually lead to that, unless it > was causing increased load resulting in slow responses or connection > failures, or if the box has some sort of attack mode where it would start > blocking connections earlier. > > Brandon > > On Thu, Feb 25, 2016 at 3:04 PM, Adrian Neale (iComms) <[email protected]> > wrote: > >> Hi there, not sure what the correct protocol for answering these things >> is, but here goes so at least you know it has been resolved. >> >> After looking at the logs myself from the shell of the Sophos UTM, the >> UTM was in fact Greylisting. >> >> Why Sophos did not originally spot this when I raised the call with them >> I do not know. Also, why is it only affecting Hotmail/Gmail/Outlok.com, I >> do not know. >> >> Anyway, so the emails are following the right MX records in the right >> order. >> >> They are getting Greylisted and are arriving at the 3rd priority MX >> record queuing service (which does not Greylist) and are being delivered >> back up to the primary MX record. >> >> So all behaving as expected, well, kind of, but at least I know why. >> >> Thank you for all your suggestions, they helped me identify and >> understand the problem with a bit of digging on my part. >> >> Kind Regards, >> >> Adrian. >> _______________________________________________ >> mailop mailing list >> [email protected] >> https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop >> > > > _______________________________________________ > mailop mailing list > [email protected] > https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop > >
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