Resonant long-range interactions between polar macromolecules

► We reinvestigate the issue of long-range resonant interactions between two oscillating dipoles, in particular when field retardation effects are relevant. ► Our main results have been computed classically and we show how they are related with quantum computations. ► We find that besides resonance condition, long-range dipolar interactions are effective when the interacting system is out of thermal equilibrium. ► We show that retardation effects yield very long-range interactions proportional to 1/r2 and 1/r never reported before in classical context.