If you have someone willing to do that for you, make sure your app is 100% ready when they submit their recommendation. It would be a waste to have it scored in any condition but perfect. Have a dozen people (or more), including the person submitting the recommendation, review it for errors. Everyone sees different things and can give you suggestions/corrections/improvements. Some suggestions may conflict, so take them all with a grain of salt and remember, it's your application.

Also, the recommending pilot doesn't need to use their '@delta.com' email address; their employee number is enough to prove their employment status.

There is an instruction document on dlnet that tells how to submit an internal pilot recommendation.