A method and relay for relaying messages. The relay includes tests reliability relating solely to messages estimated with error and taken in their form prior to error detection in order to be able to separate messages that are reliable and messages that are not reliable. The relay also includes a shaper unit having a channel interleaver and a modulator taking account only of the messages estimated without error and of those messages estimated with error that are reliable, this shaping being performed in soft form if at least one message estimated with error successfully passes the reliability test.