4. Verify the user availability setup

When your users start using Calendar Interop, you can check their activity and status in the Calendar log events of the audit and investigation page. For details, go to Calendar log events.

If you encounter errors in the Calendar log events, go to Calendar Interop error messages & codes for troubleshooting information.

You must be signed in as a super administrator for this task.

1. Sign in to your Google Admin console.

   Sign in using an account with super administrator privileges (does not end in @gmail.com).

2. In the Admin console, go to Menu  AppsGoogle WorkspaceCalendar.
3. Click Calendar Interop management.
4. For Troubleshooting tools, click User availability lookup tester, enter the email address of a user in your organization, using one of the following options:
   • To verify whether an Exchange user can query the availability status of a Google Calendar user, enter the email address of a Google Workspace user.
   • To verify whether a Google Calendar user can query the availability status of an Exchange user, enter the email address of an Exchange user.
5. Click Perform test.

The tool issues an availability query for the user and includes a request and response. If the request was unsuccessful, you get an error summary. To troubleshoot errors, go to:

• Troubleshoot Calendar Interop issues
• Calendar Interop error messages & codes

If you receive this error, you need to check the Exchange-initiated connection to the autodiscover endpoint. One possible issue is Exchange only allows connections in TLS 1.0 while Google Calendar requires TLS 1.2.

To resolve this error, update Exchange to the latest service pack and cumulative update. Then, turn on TLS 1.2 through the Microsoft Windows registry. A system restart might be needed afterwards. For more information on TLS registry settings, consult this Microsoft article.

If this process doesn't resolve the issue, follow these general troubleshooting steps to investigate further:

1. Install a packet capture tool (for example, Wireshark) on the Exchange server.
2. Start a packet capture on the machine.
3. Open a command prompt (CMD) window.
4. To empty the DNS cache, enter the following command:

   ipconfig /flushdns

5. Reproduce the issue by trying to retrieve Google Workspace user availability from Exchange in the troubleshooting tool. Make sure you receive the same "Autodiscover endpoint couldn't be discovered" error.
6. Stop the packet captures.

Analyze the packet capture results to find packets containing the name of your autodiscover endpoint (for example, autodiscover.googleworkspace.altostrat.com), or the IP address of your web server. It details the way that Exchange is attempting to connect to the web server, and should reveal where it's unsuccessful.