If the mass of a photon at rest is zero, when it is NOT at rest, moving at the speed of light, does it have mass then?

A volume of mass in space exists if it can move accordance to this equation; Energy of motion = mass x distance traveled ^2 / time ^2.There cannot be any mass motion without describing its energy.

No energy , zero mass,zero speed.

The Universe is in continuous motion.That means something with no mass cannot move ;hence cannot exist as an entity.

No, it doesn't have mass but it has energy and momentum.

A photon can never be at rest.

It's only for massive particles that the mass corresponds to an energy at rest. Otherwise we have to use the general definition of the mass, which is the square root of the scalar invariant s = p_mu p^mu, with p_mu being the momentum quadrivector. For a massless particle you cannot find any change of referential such that p = (p_0,0,0,0).

actually yes..that is how the photon can cause momentum.. it is actually not NOT MOVING so it always has relitavistic mass

notr sure why gotta put 15 characters