Microsoft Exchange Autodiscovery Service Configuration Is Not Secure

This Error event indicates that the Microsoft? Exchange Autodiscover service was unable to process anonymous requests from an Autodiscover client, for example, an Outlook? client. An invalid Autodiscover site configuration and an anonymous client request could cause this error. ‘HostName’ in the error message text refers to the Domain Name System (DNS) name of the remote client. Autodiscover requires authenticated clients to connect by using either of these methods: The client may use a Secure Sockets Layer (SSL) connection to perform Active Directory? directory service lookups to find the requested mailbox database. The client may provide URLs of Exchange services such as the Availability service. We do not recommend that you enable anonymous authentication as this will give spammers access to e-mail addresses. A HTTP 403 error is sent to the client.

Last modified April 17, 2020