To provide a method for transmitting short messages (SMS) between computers (3, 8, 9) in the Internet (4), wherein the short message (SMS) is converted into a data format comprised of a header part (10) and a useful part (32), with at least one data field (11) for determining the data format, at least one data field (16) for identifying the sender, and at least one data field (19) for identifying the recipient being inserted into the header part (10), it is provided that before, during and, optionally, after the transmission of the short message (SMS), character strings (.LOGIN, .SELECT-CHANNEL) are exchanged between computers (3, 8, 9). By using the data format described in combination with the character strings which are exchanged between the computers (3, 8, 9), a protocol (ISMTP, Internet Short Message Transfer Protocol) that is suitable for such a data transfer and variable can be created which is based on a computer network, e.g. a TCP-IP-based network. By using this data format, a protocol suitable for such a data transmission (ISMTP Internet Short Message Transfer Protocol) can be created which is based on a computer network, e.g. a TCP-IP based network.