In the first part of the present work, the correction to the photon emission rate of an oscillating two-level atom in the presence of an electromagnetic quantum vacuum field has been investigated for two different configurations: (i) an atom is trapped in the vicinity of a perfect conductor and (ii) an atom is trapped between two perfect conductors. In the second part, the correction to the decay rate of an initially excited oscillating two-level atom due to the presence of a perfectly conducting surface is found.