  In this work we investigate the L^p-L^q-mapping properties of the resolvent
associated with the time-harmonic isotropic Maxwell operator. As spectral
parameters close to the spectrum are also covered by our analysis, we obtain an
L^p-L^q-type Limiting Absorption Principle for this operator. Our analysis
relies on new results for Helmholtz systems with zero order non-Hermitian
perturbations. Moreover, we provide an improved version of the Limiting
Absorption Principle for Hermitian (self-adjoint) Helmholtz systems.
