An electric field is a field that permeates and is permitted at the rate of one divided by the permittivity of free space. What would make you think it wouldn't pass thru the massive distance between atoms? That's in fact free space. The distance between atoms is quite large in relation to the size of the atom. There is a huge amount of free space area like outerspace in the atomic structure of a metal conductor. Is there something that would stop an electric field from permeating thru the conductor's free space?
Its like a gravity field, in fact they are very similar in falloff and geometry just one's more powerful then the other. But they're both fields that permeate.
Can the earths gravity be felt on the other side of the moon? Of course it can, likewise the electric field of a parallel plate dipolar device could easily permeate thru the atoms in a conductor and likewise be felt on the other side of the atoms within it.
Its just simple field mechanics. The evidence is the gravitational forces out in space. We have no reason to beleive that the field from an electric force does not behave similar tot he field of a gravitational force. Do we?
But if you would like to conduct an experiment, put one pole of an electric plate on one side of a conductor and the other pole plate on the other side and see if they attract each other, if they do then they definately permeate thru the conductor from the source of the field which is the plates.
In similar character, and this is something you can do quite easily, take two magnets and put them on each side of a conductor and see if they attract. its a field just like the electric and gravitational fields. An aluminum plate will do perfect for the conductor.
I think you are refering to the electric field created by electron chaining from an electromotive force, which is entirely different mechanics.
The fields don't just exist everywhere, they are radiated from a source. And if they are radiated and have an origin where the source is, then passing thru something and reaching the other side means that it is in fact passing thru and exists on the inside as well.
How do you think permanant magnets are made? The magnetic field is permeated thru a conductor which is heated and the atoms are affected and align with the magnetic field which is then cooled and they retain their alignment.