This publication discloses a method for delivering messages in a telecommunications network (1, 2, 6, 11, 12). In the method, the first text-form message (40) of the session N is delivered (43) to the user of the service, in such a way that the sender address (e.g., the A number) is converted to correspond to the session number N and the session stage J, in stages 2-n (41) of the session N, a text-form message (40) is received, from the user of the message service, at the sender address defined in the message in the previous stage, and the session proceeds according to the contents of the message (40), in such a way that the sender address (e.g., the A number) is converted to correspond to the session number N and the new session stage J, and the next text-form message of session N is sent to the user of the message service. According to the invention, in some stage of the session N, a voice message is received (42), from the user of the message service, at the sender address of the message defined in the message (40) in the previous stage, or at an address contained in the message, and the session proceeds according to the content of the message (40), and if necessary, the next text-form message of the session N is sent to the user of the message service, in such a way that the sender address (e.g., the A number) is converted to correspond to the session number N and the new session stage J.