The list of custom message class names contains incorrect formatting. These are the guidelines for the list: Use the fully ...

The list of custom message class names contains incorrect formatting. These are the guidelines for the list:
Use the fully qualified message class name (for example: IPM.Note.Contoso).
Use semi-colons to separate multiple message class names.
Do not include standard Outlook message classes, such as IPM.Note or IPM.Contact.