A heat exchanger, in particular a charge air cooler or an exhaust gas cooler for an internal combustion engine, comprising a plurality of essentially parallel tubes and at least one collector box on the output side, the tubes each emptying into the collector box on the output side, and a gas flow flowing from the tubes into the collector box and from the collector box into an outlet of the collector box, a structure for interacting with the gas flow being provided at least one of the tubes or collector box, a condensation being transported to the outlet with the aid of the structure.