The General Handbook,
8.9, contains the policies and procedures for the sacrament. In
18.9.2 it states "Teachers, priests, and Melchizedek Priesthood holders may prepare the sacrament." "Priests and Melchizedek Priesthood holders may bless the sacrament." and "Deacons, teachers, priests, and Melchizedek Priesthood holders may pass the sacrament." Without being physically present it is not possible for them to perform the ordinance.
As far as nonmembers partaking of the sacrament General Handbook,
18.9.3, states "Although the sacrament is for members of the Church, nothing should be done to prevent others from partaking of it."