Why has Microsoft been routing example.com traffic to a company in Japan?

Summary

When asked early Friday afternoon why Microsoft was doing this, a representative had no answer and asked for more time. By Monday morning, the improper routing was no longer occurring, but the representative still had no answer. The new JSON response suggested that, as of Monday morning, Microsoft hadn’t fixed the configuration routing traffic to the Sumitomo Electric servers. Instead, the JSON response no longer occurs. Where the output was occurring on Friday, the command simply sits and hangs for 10 or 20 seconds and then terminates with a not found error. This behavior can be seen in the following output: > GET /autodetect/detect?app=outlookdesktopBasic HTTP/2 > Host: prod.autodetect.outlook.cloud.microsoft > Authorization: Basic ZW1haWxAZXhhbXBsZS5jb206cGFzc3dvcmQ= > User-Agent: curl/8.14.1 > Accept: */* > * Request completely sent off * TLSv1.3 (IN), TLS handshake, Newsession Ticket (4): * TLSv1.3 (IN), TLS handshake, Newsession Ticket (4): < HTTP/2 204 < date: Mon, 26 Jan 2026 18:23:55 GMT < server: Kestrel < strict-transport-security: max-age=2592000 < x-olm-source-endpoint: /detect < x-provider-id: Unknown < x-debug-support: eyJkZWNpc2lvbiI6ImF1dG9EdjIgPiBhdXRvRHYxID4gZml4ZWQgZGIgcHJvdmlkZXIgPiBmaXhlZCBkYiBkb21haW4gcHJvdG9jb2xzID4gZGIgcHJvdmlkZXIgPiBkYiBkb21haW4gcHJvdG9jb2xzIiwiYXV0b0QiOnsidjIiOm51bGwsInYxIjpudWxsfSwiZGIiOnsicHJvdmlkZXIiOm51bGwsImRvbWFpbiI6eyJmaXhlZCI6ZmFsc2UsImF1dG9EdjJFbmRwb2ludCI6bnVsbCwicHJvdmlkZXJJZCI6bnVsbCwicHJvdG9jb2xzIjpudWxsfX19 < x-autodv2-error: ENOTFOUND “It looks like they may have outright removed the endpoint that validates the email, because I’m seeing ‘not found’ errors,” said Dan Tentler, founder of Phobos Group. As denoted by ENOTFOUND, the error “suggests that [Microsoft admins] just ripped out whatever this thing was.” It’s unclear how Sumitomo Electric’s domain would have found itself part of this mess. Microsoft last year said the Japanese company’s parent company, Sumitomo Corp., was deploying Microsoft 365 Copilot,...