Confirm service and internet
Verify internet access, Microsoft service status and the user account sign-in independently of Outlook.
Check credentials and MFA
Confirm password, MFA prompts and account lock status. Remove stale credentials only when justified.
Test profile configuration
Check account settings, Autodiscover behavior and mailbox connectivity. Use a new profile as a controlled comparison.
Protect local data
Before deleting profiles or PST files, confirm where user data is stored and whether a backup is required.
Use this as a practical starting point. Follow your organization's policies, licensing requirements and vendor documentation for production changes.