The MLX phones don't have a "well" in them to allow for the part of the wall jack that sticks out. If you have the typical wall mount jack that consists of a metal cover, and metal back plate, and a plastic jack module, you can seperate the jack module from the back plate - plug in the line cord and push them into the wall. Mount the back plate, feed the line cord out through the bottom (not through the hole in the moddle of the face plate), screw on the face plate. Now you have a metal faceplate, with a rectangular hole in the middle, but with the two mounting ears on the top and bottom and a short line cord feeding out of the bottom. Plug the line cord in the bottom of the phone, and mount it to the mounting ears.