Movie: What movie is this?

Question

Mom wrote fake letters to son from dad who she said was shipped out or something. Then something happens and she has to find someone to substitute for the father who actualy does not exist? Something to that effect. Came out in the last year or so?

Answer 1

Dear Frankie...

After having responded to her son's numerous letters in the guise of his father, a woman hires a stranger to pose as his dad when meeting him