Hello, does anyone have a Microsoft contact that could help with an email deliverability issue that started approximately two days ago? We (LeapAP) are seeing a large and increasing volume of mail errors from Microsoft, such as the below (XXXX is our dedicated IP at our ESP) and are unable to deliver mail to our users with the following destination domains (so it seems like the hosted Office 365 domains aren't impacted, but only the free/Outlook.com ones): hotmail.com hotmail.ca live.ca msn.com outlook.com live.com 4.7.650 The mail server [XXXX] has been temporarily rate limited due to IP reputation. For e-mail delivery information, see https://aka.ms/postmaster (S775) SNDS shows nothing abnormal for the IP address during the involved time period or earlier, but I can only see up to yesterday @ 18:00 PT there. We submitted the Microsoft form at https://olcsupport.office.com/ and have a ticket number as a result, which I can share as well. Appreciate the help as we're quite impacted and getting a lot of support tickets. Thanks Erik Levinson LeapAP