Making use of the quantum correlators associated with the Maxwell field vacuum distorted by the presence of plane parallel material surfaces we rederive the Casimir-Polder interaction in the presence of plane parallel conducting walls. For a configuration consisting of a conducting wall and a magnetically permeable one new results for the Casimir-Polder interaction potential are obtained.In 1948, Casimir and Polder [1] taking into account a suggestion made by experimentalists evaluated the interaction potential between two eletrical polarizable molecules separated by a distance r including the effects due to the finiteness of the speed of propagation of the electromagnetic interaction, i.e.: of the retardment. Casimir and Polder showed that the retardment causes the interaction potential to change from a r −6 power law to a r −7 power law. In the same paper, Casimir and Polder also analyzed the retarded interaction between an atom and a conducting wall and showed that the interaction potential in this case varies according to a r −4 power law, where now r is the distance between the atom and the wall. For an introduction to these subjects see [2]. Here we wish to show how it is possible with the help of the so called renormalized electromagnetic field correlators, in our case the ones that take into account the presence of the boundary conditions imposed on the fields, to reobtain the piece of Casimir and Polder's result for the atom-wall interaction that depends on the distortion of the vacuum oscillations of the electromagnetic field caused by the presence of parallel walls. The electromagnetic field correlators for the case of two parallel perfectly conducting surfaces separated by a distance a were evaluated in [3] and in [4]. For the case of a perfectly conducting plane wall and a perfectly permeable plane wall, a setup first introduced by Boyer [5], they were calculated in [4]. These mathematical objects, closely related to the pertinent electromagnetic Green's functions, were also employed to obtain an alternative view of the Casimir effect [6] through the quantum version of the Lorentz force between the walls [7].Let us first recall some aspects concerning electrically and magnetically polarizable bodies [8]. From a classical point of view the induced eletrical polarization density P can be thought of as a function of the electric and magnetic fields E and B. In many cases only the dependence on the eletric field is relevant. It can be shown that under conditions for which the effects of the retardment (i.e., of the finiteness of the speed of light) must be taken into account it suffices to consider the static eletrical polarizability α (0) only, see for instance [2] and references therein. If the electric field changes by δE, the interaction between the polarizable body and the electric field will change according to δV = −P [E] · δE = −α (0) E·δE. Therefore, if the field changes from zero to a finite value E, the interaction energy is V E = −α (0) E 2 /2. In the quantum version of this interaction pote...