We will only migrate items whose type is identified by the Notes subsystem.  To check the item type associated with a Lotus Notes item:

1. Start your Notes client.
2. Select a single email.
3. Click on the File menu.
4. Click on Properties.
5. Look for the Form property​.
6. Checkmark the associated value.

You should see something like this for email:

If the Form property​ is empty, then the item type is not specified, and so we will not migrate the item.