How to Fix Outlook 504 Gateway Timeout - Outlook Error 0x800CCC0E: How to Fix SMTP Connection Issues-Run a PowerShell Script Without Changing Execution Policy
Before changing system settings, save your work and note the exact error text so you can compare results after each step.
Extra verification checklist
- Restart the affected app after changing permissions or configuration files.
- Test the same workflow in a clean browser profile or a temporary user account.
- Compare the result on another network if the error may be connection related.