said by ITGeeks:FedEx is not required to knock, nor is UPS. As long as the package is left/delivered that's all. That's why they give tracking numbers and insure their packages.
Oh im sure they arent required to, but the driver dug himself a hole by saying despite him seeing suspicious people in the area he still left the package. His story does not make sense and they have always knocked or I have heard them, especially when I am sitting 5ft from the door and was there at the alleged delivery time