1. Don’t leave any spaces between lines.
2. The name of the class must be exactly one that exists, or be left blank.
3. Email addresses should be all in lowercase.
4. Save the file; don’t change the extension (.csv).
5. Right-click the file and open it on Notepad.
6. File->Save->As.
7. Select Type ‘All Files’ and Encoding ‘UTF-8’.
8. Save the file.