> On 2016-02-14 18:34, Bill Cole wrote: > >> are there any legitimate (non-spam) senders, that would be blocked by >> reject_unknown_client_hostname ? > > Do you consider Microsoft's Office365 to be "legitimate?" > > They send substantial non-spam, yet many of their output IPs have PTR > addresses which yield addresses which do not resolve back to the > original IPs.
sorry for keep dwelling on this, but is there any reason why a legitimate sender (ie Microsoft) would not use corresponding IP -> hostname -> IP ? Is there some technical limitation that prevents them from doing it?
