An exact solution using the Wiener-Hopf technique is derived for a rewetting model. In this mixed-boundary model, a constant heat transfer coefficient is assumed in the wetted part of the solid slab, whereas an exponentially decaying heat flux is assumed in that part of the solid that is cooled by a mixture of vapor and liquid droplets (the precursory cooling). The solution, which is of a simple form, is found to be in excellent agreement with a solution by separation of variables, previously obtained for the same problem. Numerical results are presented for a wide range of model parameters.