Thank you for your responses everyone. When I checked the SNDS this morning I was very surprised to discover that Microsoft has delisted almost all IPs from 5.9.0.0/16. So 7 days after the entire range was blacklisted, it has just as suddenly been delisted.
I have no idea what caused this. If somebody was able to contact Microsoft because of this post, or somebody from Microsoft saw it and took some action, then thank you very, very much! I would obviously still love to know what caused this, and what I might be able to do to prevent something like this in the future, so if anybody has information on that to share, please do so. For fans of statistics: Microsoft is currently blacklisting 4,917 IPs (544 from 5.9.0.0/16) from our network, which is a new all-time low. To me that confirms that we are moving in the right direction and improving. Am 05.06.2019 um 17:31 schrieb Michael Rathbun via mailop: > I recall that, about six years back, I put in a block rule for an entire /15 > in the 5.0.0.0/8 range. That was for EOP/Office 365, though. In the > subsequent months a total of two false-positive reports flooded in. I don't > recall it being in the area you mention. Plus you would have noticed it > earlier, I would expect, if that rule is still in effect.. That's really interesting, thanks for sharing Michael. I was under the impression that the Microsoft blacklist, at least the one for Outlook, and not O365, was an automated system. Do you know if it is still possible to manually add blocks? Maybe that happened here? Kind regards Bastiaan van den Berg --------------------- Hetzner Online GmbH _______________________________________________ mailop mailing list mailop@mailop.org https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop