Debugging is very important step in the mapping process. The snapADDY DataQuality has a powerful debug console, that can be opened by pressing [F12] in the DataQuality window. This opens a new DevTool debug console window.

You can see what will be exported to the CRM by looking at the "EntityMapping" logs. Every entity in the mappings should appear in the Console. Expand the log to see what the mapping for the entity returned (Mapping returned).