Microsoft Remote Connectivity Analyzer Tool

When a Microsoft 365 service stops working, the visible symptom is often only the tip of the problem. An issue such as “Outlook cannot connect to Exchange Online” could point to DNS problem, a broken Autodiscover record, an authentication failure, an expired certificate, or a simple misconfiguration.

Administrators often need to investigate several of these possibilities across the dependency before they can determine where the failure is occurring. If the issue is eventually escalated to Microsoft Support, admins may be asked what they have already tested and what the results showed.

This is where the Microsoft Remote Connectivity Analyzer (RCA) can help administrators move from a reported symptom to a more focused diagnosis. In this blog, we’ll explore what the RCA tool is, the diagnostic tests it offers, and how administrators can use them to troubleshoot Microsoft 365 service issues.

Microsoft Remote Connectivity Analyzer (RCA) is a free, web-based diagnostic tool from Microsoft, commonly accessed through the Microsoft Test Connectivity portal. It helps administrators pick a test that matches their scenario to troubleshoot Microsoft service problems. RCA runs a series of checks remotely from Microsoft’s own infrastructure rather than from the admin network.

Depending on the test, RCA evaluates areas such as account requirements, DNS and domain configuration, service endpoint accessibility, certificate and TLS configuration, and more. Each check RCA tool returns one of three results like success, warning, or failure along with built-in guidance to help you understand what the result means and what to check next.

Consider an administrator who receives a support ticket stating:

“Users can sign in to Microsoft Teams, but they cannot make or receive calls.”

While Teams sign-in is working, the Teams calling issue could have several underlying causes.

Instead of manually investigating each possibility one by one, the administrator can open the Microsoft Remote Connectivity Analyzer and select the appropriate test.

In general, running any RCA test follows the same pattern. RCA then performs a series of diagnostic checks for the selected scenario. For a Teams calling-related issue, the tool runs the investigation that can be viewed conceptually as:

RCA tool Teams client

↓

DNS Test resolution → Passed / Failed

↓

Service endpoint → Passed / Failed

↓

Authentication → Passed / Failed

↓

Network connectivity → Passed / Failed

↓

Calling-related checks → Passed / Failed

Once the test is complete, admins can analyze and interpret RCA test results to identify where the issue resides.

Microsoft Remote Connectivity Analyzer provides different test scenarios for specific Microsoft services and workloads, such as:

• Exchange Online
• Exchange Server
• Microsoft Teams
• Skype for Business Server
• Microsoft Copilot

Along with the workload-specific tests, RCA also includes a Message Header Analyzer and a Microsoft 365 Network Connectivity Test tool. Each service category contains tests designed to validate particular connectivity or configuration requirements.

Let’s dive into the diagnostic tests available under each service in detail.

Exchange Online tests help diagnose Outlook connectivity, mail flow, DNS issues, and more. The different Exchange Online tests released so far are listed below.

It’s also important to learn about the troubleshooting options in Exchange to understand the collection of diagnostic logs for Exchange Online issues.

For on-premises Exchange environments, the RCA tests focus on how external clients and services reach your server. Common tests cover Exchange ActiveSync, Exchange Web Services, SMTP, and SSL. For additional Exchange Server tests and their purposes, refer to the table below.

RCA provides scenario-specific tests for Microsoft Teams rather than treating Teams as a single service. Administrators can use these tests to investigate common issues such as Teams sign-in and guest access, Exchange and calendar integration, calling and meetings, Rooms and Shared Channels, etc.

For other Teams scenarios covered by RCA, refer to the test details in the table below.

If you still run an on-premises Skype for Business Server, RCA offers two remote connectivity checks:

For supported Microsoft Copilot scenarios, RCA can validate the conditions required for specific Copilot capabilities. The available tests cover Copilot licensing, Copilot agents in Microsoft Teams, and Copilot connectors, helping administrators investigate eligibility, functionality, and connector-related issues.

Case: A Team owner can’t add a guest user to the Team

Suppose a Team owner tries to add an external guest user to a Microsoft Team, but the invitation fails. The cause could be tenant guest access settings, Microsoft 365 group settings, team ownership, or another prerequisite.

Checking each setting manually can make it difficult to isolate the exact cause. The Remote Connectivity Analyzer helps identify the problematic prerequisite by diagnosing the issue step by step. The initial investigation shows that the user can sign in to Teams, collaborate normally, and is even a Team owner, but still can’t add a guest!

For this scenario, the Guest Invite to Team test is the right test as it checks whether a guest user can be invited to a Team, including tenant guest access, group settings, and team ownership.

Before running the tool diagnostic test, it’s necessary to ensure the following requirements are satisfied.

• Ensure to use supported, up-to-date browsers like Microsoft Edge, Google Chrome, or Mozilla Firefox.
• Allow the required RCA IP addresses to allow inbound connections through firewalls or network perimeters for successful diagnostics.
• RCA requires Global Admin authentication and permissions for certain service-specific tests.

1. Open the Microsoft Test Connectivity Tool in a browser.
2. Select Microsoft Teams under Connectivity Tests Category and, then choose the Guest Invite to Team test.
3. Enter the required inputs such as account authentication and the link to the Team you can’t add the guest to.
4. Complete the prompted security verification and acknowledgement.
5. Now, click on Perform Test to run the diagnosis.

RCA performs a series of checks against the prerequisites required to invite and add a guest to the Team. Once the test completes, the results show the status of each check and highlight any areas that require attention.

If all checks are successful, the required prerequisites for adding the guest are satisfied. In this case, the administrator can continue investigating other possible causes, such as user-specific issues or recent configuration changes.

If a test passes but the issue still happens in your environment, the cause may be client-side, network-path specific, or intermittent. In that case, export the test result in HTML format and attach it when you raise a support request.

If the check is passed with warnings, then the test has been completed successfully, but RCA has identified a condition that may require attention. The administrator can review the warning details and determine whether it could affect the guest invitation.

If a check fails, follow the troubleshooting guidance to identify the configuration or prerequisite that requires attention. For example,

• If the test identifies an issue with tenant guest access, review the organization’s guest access settings.
• If it identifies an issue with Microsoft 365 group settings, investigate the settings that control guest access for groups and Teams.

As a quick reference alongside the walkthrough above, here’s a table on Configuration or Connectivity test result:

Tip: Choose the troubleshooting tool based on the issue. For Teams issues, refer to Microsoft’s Admin self-help diagnostics to find the right diagnostic.

Other Microsoft Service Tests for Guest-Related Issues

Other Teams tests that may help depending on where the guest-related issue occurs. The appropriate RCA test depends on where the guest experience is failing.

• Teams Guest Sign in: Use this when the guest has already been invited but cannot sign in to Microsoft Teams.
• External User Meeting Join: Use this when the guest user has trouble joining a Teams meeting. The test checks areas such as federation, lobby settings, identity types, and cross-tenant access.
• Teams Shared Channel Add Member: Use this when the issue involves adding your guest users to a Teams shared channel.

Considerations for Remote Connectivity Analyzer Tool

• RCA is currently unavailable for Microsoft 365 Government environments such as GCC and GCC High.
• Check Microsoft 365 Service Health before running a test, to rule out known service incidents.
• Apply troubleshooting guidance only when the corresponding error or failure is reported by the RCA test.

Along with service-level diagnostics for Microsoft 365 services, Microsoft also provides diagnostic and analysis tools for email message and network troubleshooting.

A Message Header Analyzer is the technical information attached to an email that records details such as the sender, recipient, mail servers, routing, and timestamps. Message Header Analyzer tool analyzes these headers. Use this tool to trace an email’s path through the mail servers it passed through, and to check whether a message that claims to be from Microsoft is genuine.

The tool breaks down mail-flow, routing, delivery, latency details and helpful for tracking down a delayed or misrouted email.

This helps to identify network-level connectivity issues between your network and Microsoft 365 service endpoints that may affect access to Microsoft services.

For example, administrators can use this tool when users in a specific office location report broken page loads while accessing SharePoint sites, Outlook on the web, or Microsoft admin center pages, particularly when a network-level issue is suspected. To use it, open the Network Test tool, select the appropriate location, and run the test.

Conclusion

Thus, whether you’re troubleshooting Teams, Exchange, or other supported Microsoft services, RCAT provides a practical way to validate connectivity and configuration before escalating an issue. Admins can use the test results to identify potential issues, narrow down the cause, and gather evidence for troubleshooting or escalating to Microsoft Support.

We hope this guide helps you make better use of Remote Connectivity Analyzer whenever you need to investigate Microsoft 365 related issues. As Microsoft continues to introduce new diagnostic scenarios and tests, the tool can remain a useful first step in your troubleshooting process.