A tennis buddy flies in the F-27 FO seat with Mountain Air Cargo. They are another FEDEX feeder. There is no "flow-through" agreement at all. None. If an experienced pilot has worked in another FEDEX dept, whether in Admin, or other ground operations, they might be able to receive an interview with Flight Personnel. I met a guy about 15 years ago who was a pilot with an Air National Guard (C-130) squadron and drove their delivery trucks. After years of hard work and dedication, he was hired as B-727 FE as are other new-hires.
A guy at my company who flew four-engine Air Force jets (KC-135s or AWACS; was also an Instructor Pilot on it)) has thousands of hours in fairly heavy jets. Ironically, he was told by someone with the FEDEX (i.e.) Flight Personnel dept that if he applied, he would not get selected because he already had his "chance" with another major airline. Strange as it sounds, the guy with Personnel or Human Resources etc is a former Eastern Airlines pilot. I learned this today second-hand, and have flown with the excellent pilot who contacted the FEDEX gentleman.
Doubt that this info can help you very much. Good luck,
but do you have idea how many thousands of pilots are laid-off in the US and despite having years in turboprops and/or jets, only a fraction can get hired with any "decent" flying job right now. To say it is very, very competitive is quite an understatement, and wish somebody could prove me wrong, very soon.