Also seeing DNS failures (SERVFAIL) on looking up A records for the domain-com.mail.protection.outlook.com where we send the inbound messages to. Because of this we're NDRing mail instead of deferring. This one's going to be messy.
PG From: mailop <[email protected]> On Behalf Of Eric Tykwinski via mailop Sent: 22 January 2026 20:20 To: 'mailop' <[email protected]> Subject: Re: [mailop] Microsoft 365 DNS failure? Mark, We are seeing the same thing. It's on the portal: <https://status.cloud.microsoft/m365/referrer=serviceStatusRedirect> https://status.cloud.microsoft/m365/referrer=serviceStatusRedirect More info: More info: Users may be receiving a "451 4.3.2 temporary server issue" error message when attempting NkdkJdXPPEBannerStart External Sender - From: (Eric Tykwinski via mailop <[email protected]>) This message came from outside your organisation. NkdkJdXPPEBannerEnd Mark, We are seeing the same thing. It's on the portal: <https://status.cloud.microsoft/m365/referrer=serviceStatusRedirect> https://status.cloud.microsoft/m365/referrer=serviceStatusRedirect More info: More info: Users may be receiving a "451 4.3.2 temporary server issue" error message when attempting to send or receive email through Outlook. Some of the impacted service functions include, but may not be limited to: - Sending and receiving email through Exchange Online, including notification emails from Microsoft Viva Engage. - Accessing the service portals, including Microsoft Purview, Microsoft Defender XDR, and the Microsoft 365 admin center. Current status: We've identified a portion of dependent service infrastructure in the North America region that is not processing traffic as expected. This is impacting our load balancing processes and general service availability. We're working to restore this infrastructure to a heathy state and rebalance the service traffic to achieve recovery. Scope of impact: Any users served through an affected section of service infrastructure in the North America region may be intermittently impacted. Sincerely, Eric Tykwinski TrueNet, Inc. P: 610-429-8300 From: mailop < <mailto:[email protected]> [email protected]> On Behalf Of Mark Alley via mailop Sent: Thursday, January 22, 2026 3:06 PM To: mailop < <mailto:[email protected]> [email protected]> Subject: [mailop] Microsoft 365 DNS failure? Hey all, anyone else seeing DNS issues with *.mail.protection.outlook.com FQDNs? Our queues for mail to EXO tenants is growing steadily due to either deferrals or DNS lookup failures. - Mark Alley
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