An electrical receptacle connector includes a metallic shell and one or more insertion modules. The metallic shell includes two first walls, two second walls, and several protrusions. The walls form an insertion space. The protrusions are extending toward the insertion space from the first walls, and the protrusions are integrally formed on the first walls seamlessly. The insertion module includes an insulated housing, first receptacle terminals, second receptacle terminals, and a grounding plate between the first receptacle terminals and the second receptacle terminals. When the electrical receptacle connector is mated with an electrical plug connector, the protrusions are in contact with a metallic shell of the electrical plug connector. Because the walls of the metallic shell are seamless, the connector assembly of the plug and receptacle can be waterproof. Moreover, the contacts between the protrusions and the electrical plug connector reduce the electromagnetic interferences and the radiofrequency interferences.