You submit your AirlineApps with the Delta pilot's recommendation attached and filled out as it says. Next, have the same pilot email our Pilot Selection office from their Delta email account. This email can be a copy of what they put in your AirlineApps or be just as simple as “I recommend (insert name).” it does not need to be detailed because this email is to verify the recommending pilot's employment. It also triggers the app review which is what will really speak for the applicant.

And, yes, make sure the app is as perfect as can be when submitting before the app is scored.