Good Artwork but Animation Needs Improvement
You are clearly a very talented artist when you try because Scott is drawn very well (I am not sure if he had red hair but that's okay). The background was also crisp but certain drawings could be improved such as the mailbox.
Unfortunately, the animation was weak at times and that really detracted from the submission. Other areas that you should work on include the preloader (as you acknowledged), the sound, and developing a plot. Not having a plot is okay for a short film such as this one but becomes a glaring issue when you begin to create feature-length submissions.
All in all, your artwork shows promise and I am confident that you can improve your animation skills with time. Good job.