The logs for Outlook are… Interesting… Diagnostics are difficult without logs. They used to be at ~/Library/Containers/com.microsoft.outlook/ Data/Library/Logs/ or
To enable logs, open Outlook and then click on Window and then click Sync Errors.
From there, click on the cogwheel and then check the box for “Turn on logging for troubleshooting”
Now go ahead and quit Outlook and open it again. When prompted, click “Leave Logging On” and then when you get errors, open the logs.
Once enabled, you’ll see logs at ~/Library/Group Containers/UBF8T346G9.Office/OfficeLogging/. You can edit a maximum size for the log files using defaults to send a EWSMaxLogLength key to com.microsoft.Outlook using the following command:
defaults write ~/Library/Preferences/com.microsoft.Outlook EWSMaxLogLength 64