Microsoft has been sending test credentials to a company in Japan, which is located in the domain example.com, a domain reserved for testing purposes. The reason behind this anomaly lies with Microsoft's autodiscover service.
Autodiscover is used to automatically configure email accounts on devices such as Outlook desktop apps. However, due to a misconfiguration of its service, Microsoft's systems started routing traffic destined for example.com to the subdomains imapgms.jnet.sei.co.jp and smtpgms.jnet.sei.co.jp, which belong to Sumitomo Electric.
When users tried to set up an Outlook account on an example.com domain, they would inadvertently send test credentials to these seijip domains. The misconfiguration resulted in unwanted traffic being sent outside of Microsoft's networks.
However, Microsoft confirmed that the issue has been resolved after updating their autodiscover service to no longer provide suggested server information for example.com. But, it appears that the updated service still results in a "not found" error due to removed endpoint validation.
Experts are not convinced about the routing being intentional but think that there was an error on Microsoft's part, as the system is now showing signs of removal.
In general, using example.com would be considered bad practice for production purposes.
Autodiscover is used to automatically configure email accounts on devices such as Outlook desktop apps. However, due to a misconfiguration of its service, Microsoft's systems started routing traffic destined for example.com to the subdomains imapgms.jnet.sei.co.jp and smtpgms.jnet.sei.co.jp, which belong to Sumitomo Electric.
When users tried to set up an Outlook account on an example.com domain, they would inadvertently send test credentials to these seijip domains. The misconfiguration resulted in unwanted traffic being sent outside of Microsoft's networks.
However, Microsoft confirmed that the issue has been resolved after updating their autodiscover service to no longer provide suggested server information for example.com. But, it appears that the updated service still results in a "not found" error due to removed endpoint validation.
Experts are not convinced about the routing being intentional but think that there was an error on Microsoft's part, as the system is now showing signs of removal.
In general, using example.com would be considered bad practice for production purposes.