Back in May Microsoft released the beta for a new support tool called the Microsoft Office 365 Support and Recovery Assistant.
This tool can be downloaded from here
This tool can be used to help troubleshoot Office 365 account or profile related Outlook issues. When you launch this tool, you will be asked for your O365 credentials
Once authenticated, you will be prompted to select one of two scenarios for troubleshooting
For the first scenario, the tool must be run on the affected client. The tool will then run a series of checks to help identify the root cause of the issue
It will then list any issues found and offer suggestions to fix
There are more scenarios in development, so please leave feedback to help improve this very useful tool