Communication terminal device, communication method and electronic mail server

A communication terminal device comprising:

• means for establishing a connection by a call control protocol with a destination device designated by an Internet Protocol (IP) telephone number;
• means for requesting a presentation of a plurality of communication protocols which the destination device can support over the connection;
• means for selecting one communication protocol which the communication terminal device can support from communication protocols presented by the destination device as a response to the request by the means for requesting;
• means for communicating with the destination device over the connection by the communication protocol selected by the means for selecting;
• and
• means for storing a communication protocol and an IP telephone number by associating one with the other;
• wherein when a communication protocol is stored in the means for storing by being associated with the IP telephone number of the destination device, the means for requesting does not request a presentation of a plurality of communication protocols which the destination device can support over the connection, and the means for selecting selects the communication protocol associated with the IP telephone number of the destination device and stored by the means for storing, and
• wherein when a communication protocol is not stored in the means for storing by being associated with the IP telephone number of the destination device, the means for requesting requests a presentation of a plurality of communication protocols which the destination device can support over the connection, and the means for selecting selects one communication protocol which the communication terminal device can support from the communication protocols presented by the destination device.