Steps To Resolve
Here are the steps to map the NetSuite email address to the Gmail address:
1. Create a "Celigo Employee Gmail" custom record type.
Switch to Administrator role. Go to Customization > List, Records & Fields > Record types.
2. Look for "Celigo Employee Gmail" and click "New Record".
3. Specify Employee field and fill out the Gmail Address field and hit Save.
The Gmail address is now linked to the NetSuite email address.