Symptom
Daylite displays the following message when attempting to look at an email imported into Daylite. 
Why is this Occurring
The Preview pane is not/was not open inside of Apple Mail when the email imported into Daylite.
Solution
Click and drag the arrow until the preview pane is exposed.
Examples
Standard Apple Mail Format: 
"Classic View" Apple Mail format:
Note: When you have made the change above, you'll have to add the email for it to appear in Daylite.