That's volume throttling, not IP blocking. Did you recently bring a new block online, or ... someone sending out an abnormally large volume of mail? If it's going out thru shared IPs, that could also be part of the problem, but this is just speculation.
Aloha, Michael. -- Michael J Wise Microsoft Corporation| Spam Analysis "Your Spam Specimen Has Been Processed." Open a ticket for Hotmail<http://go.microsoft.com/fwlink/?LinkID=614866> ? From: mailop <mailop-boun...@mailop.org> On Behalf Of Andreas via mailop Sent: Wednesday, October 11, 2023 2:13 AM To: mailop@mailop.org Subject: [EXTERNAL] [mailop] outlook.com 421 try again later S77719 Hello all, since a few hours we have problems with sending to Microsoft. We get hundreds of messages like in the subject with the reference to S77719. Also colleagues from other companies in germany are seeing the same in their logs. All mails that are blocked here are from Microsoft customers, but they are redirected through our servers. Trying to unblock the IP e.g. via https://sender.office.com/ shows that the IPs are not blocked. Anybody have any idea? Thanks a lot Andreas
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