Dear Professor ***,
I hope my letter finds you well.
I am writing you today with much trepidation knowing that it is unusual for students to send professors letters of this nature. But I am nevertheless mustering every ounce of courage that I have right now to proceed with this letter, since I have learned that there is no harm in trying or even continue reaching for even what seems to be very impossible.
Just recently, I have already received my grade for the course I took with you. And after realizing that I am 4 marks shy of passing the subject, I must admit that I was greatly saddened by the recent turn of events. More than anything else, I cannot help be bothered by the fact that, on account of this lone failing mark, I may have gravely compromised the possibility of graduating this year. I was left heartbroken to say the least. I knew deep inside that I was not a perfect student to begin with. But that did not stop me from trying to perform fairly in your course. Even with certain inadequacies on my part, I was certainly aware that I was giving a fair amount of attention and dedication to complete the demands of the course in fairness to your effort as my professor, and the outpouring of support that I enjoy from my loved ones.
Professor ***, I am writing you to knock at your generous heart. With much humility on my part, and a profound respect for your professionalism, I am requesting if it is possible that you consider letting me pass this course, not anymore on account of the effort which I know I have poured into this course, but on the more compassionate consideration coming from your generosity. I have to be honest in admitting that I am now facing the prospect of not being able to graduate because of this grade. Which is why, I am fully aware of the nature of this request. And if this would mean that I have to sit on certain requirements in view of this request, please let me know. I believe that I am not a stranger to taking subjects not without difficulties; and I am sure that, with your support and understanding, I can come out from this dilemma as a wiser student.
Thank you for your kind consideration. Hope to hear from you soon.
I remain with a renewed expression of highest esteem.