Self-Help Diagnostics for Exchange Online

Managing Exchange Online efficiently requires quick problem identification and fast resolution. To empower IT teams, Microsoft has introduced enhanced self-service diagnostics within the Microsoft 365 admin center. These tools help administrators troubleshoot common issues without opening support tickets, saving both time and effort.

These self-help diagnostics for Exchange Online use advanced text analytics to scan for known issues, validate configurations, and provide step-by-step guidance to resolve problems. Although they cannot make automatic changes to your tenant without approval, they are extremely effective for detecting misconfigurations and speeding up root-cause analysis.

Why Self-Help Diagnostics Matter

Reduce dependency on Microsoft support
Resolve issues faster
Improve service availability and performance
Enable admins to identify problems proactively
Provide accurate, Microsoft-validated troubleshooting steps

Self-Help Diagnostics for Exchange Online and Outlook

Microsoft currently offers a wide range of prebuilt self-help diagnostics for Exchange Online that analyze health, configuration, permissions, delivery status, and more. Below is a simplified overview of what each diagnostic checks and what it helps resolve.

1. EWS Migration Throttling Check

This self-help diagnostic verifies that the EWS throttling policy isn’t too restrictive for a mailbox data migration that uses third-party tools. (Doesn’t apply to Microsoft tools for Hybrid, IMAP, G Suite, or Public Folder migrations.) Run Test: EWS Migration Throttling.

2. Accepted Domains Validation

This self-help diagnostic verifies whether a domain is correctly configured as an Exchange Online accepted domain, preventing delivery failures. This self-help diagnostic is useful when you get error “You can’t use the domain because it’s not an accepted domain for your organization” while adding a new user in Microsoft 365 or Exchange Online. Run Test: Exchange Online Accepted Domain.

3. Test RBAC Permissions for a User

This diagnostic helps troubleshoot when a user cannot run a specific PowerShell cmdlet due to missing roles or incorrect permissions. If a user has issues running a specific PowerShell cmdlet or command, or gets an error indicating that they don’t have the correct roles or permissions, run this diagnostic to check whether the user has permissions to run the cmdlet and the specific parameter. Run Test: EXO RBAC Test for User.

4. Compare RBAC Roles Between Two Users

If one user has issues running a specific PowerShell cmdlet or command, or gets an error indicating that they don’t have the correct roles or permissions, while another user doesn’t have these problems, run this diagnostic to compare the RBAC roles of the two users. Run Test: Compare RBAC Roles for Users.

5. Recipient Object Failure Check

Identifies and resolves common issues related to Exchange Online recipients, such as delayed mailbox provisioning or synchronization issues. This self -help diagnostic is helpful when you face issues with delays in provisioning of user/mailbox or synchronizing changes in Exchange Online Run Test: EXO Recipient Object Failures.

6. Exchange Organization Object Health

This self-help diagnostic checks health and resolve issues related to your Exchange Online organization object. For example, Exchange Online tenant provisioning or RBAC-related issues (various commands aren’t available even though users have permissions). Run Test: EXO Recipient Object Failures.

7. Mailbox or Message Size Check

This diagnostic evaluates the size of a mailbox or individual message, helping diagnose issues related to limits and quotas. Run Test: Mailbox Size.

8. Deleted Mailbox Diagnostics

This diagnostic checks the status of recently deleted mailboxes and provides recovery guidance. Run Test: Deleted Mailbox.

9. Remote PowerShell Throttling Policy

This self-help diagnostic assists in identifying restrictive throttling that might affect Exchange Online PowerShell performance. Run Test: PowerShell Throttling.

10. Email Delivery Troubleshooter

Ensures that email messages are delivered properly and identifies where failures may be occurring. Run Test: Email Delivery Issues.

11. Outlook user connectivity diagnostics

This self-help diagnostic for Exchange Online diagnoses Outlook connectivity issues for users by running several checks on possible service-side settings (root causes) so that a tenant admin can quickly fix the issues without involving the users. Run Test: Outlook Connectivity Issues for User.

12. NDR (Non-Delivery Report) Diagnostics

This self-help diagnostic for Exchange Online provides additional information about NDRs that are received through email messages. Run Test: Email NDR Issues.

13. Archive mailbox diagnostics

This diagnostic checks and identifies issues about mailbox archiving. Run Test: Archive Mailbox Issues.

14. Outlook user password prompt diagnostics

This self-help diagnostic diagnoses Outlook password prompt issues for users by running several checks on possible service-side settings (root causes) so that a tenant admin can quickly fix the issues without involving the users. Run Test: Outlook Password Prompt.

15. Retention policy diagnostics for a user mailbox

This diagnostic checks retention tags and policies applied to a user’s mailbox to ensure compliance configuration is correct. Run Test: Retention Policy not working for User.

16. DKIM Configuration Diagnostics

This diagnostic validates DomainKeys Identified Mail (DKIM) settings and checks if DNS records are set up correctly. Run Test: Check DKIM.

17. Compromised Account diagnostic

This compromised account diagnostic diagnostic identifies suspicious activities against an account and return information that can be used to recover the account if compromised. Run Test: Compromised Account.

18. Email threat policies diagnostics for a recipient

Lists the Exchange Online Protection (EOP) and Microsoft Defender for Office 365 threat policies that applied to the message. Run Test: Email Threat Policies.

19. Proxy address conflict diagnostics

This diagnostic finds the Exchange recipient that uses an email address. Helpful if you receive an “Email/proxy address is in use” or similar error message when you try to create an Exchange Online mailbox. Run Test: Proxy Address in use.

20. Mailbox safe/blocked sender list diagnostics

This self-help diagnostic for Exchange Online checks and identify issues with the mailbox’s safe senders and domains, blocked sender and domains in junk email settings. Run Test: Mailbox Safe Blocked Sender List.

Conclusion

Self-help diagnostics in the Microsoft 365 admin center offer administrators a powerful, streamlined way to troubleshoot Exchange Online and Outlook issues. With deep insights, validation checks, and clear resolution steps, these tools help reduce downtime and improve user productivity—without waiting for support response times.

If you’re managing a Microsoft 365 environment, leveraging these self-help diagnostics for Exchange Online should be a key part of your operational toolkit.

You might like our other articles on How to use MFCMAPI, Troubleshoot OOF messages using MFCMAPI, and Purge emails from Recoverable Items folder using MFCMAPI.

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