A communication apparatus comprising: input means configured to input image data; transmission means (2010,2050) configured to transmit the image data input by the input means and be capable of executing a transmission process using any of a plurality of communication systems (3006, 3007, 3008); storage means configured to store address information which is used for identifying an address to which the transmission means (2010, 2050) transmits the image data and associated with any of the plurality of communication systems; reception means configured to receive a transmission instruction to cause the transmission means (2010, 2050) to transmit the image data input by the input means based on the address information stored in the storage means; and control means configured to control the transmission means (2010, 2050) to transmit the image data input by the input means in response to the reception of the transmission instruction, based on the address information stored in the storage means, and using the communication system (3006, 3007, 3008) associated with the address information; wherein the communication apparatus is configured to delete from the storage means the stored address information, after the transmission instruction is received by the reception means and the transmission process according to the transmission instruction is ended, if the stored address information is associated with a first communication system (3006, 3007, 3008); and characterized in that the communication apparatus is configured so that the storage means keeps storing the stored address information, after the transmission instruction is received by the reception means and the transmission process according to the transmission instruction is ended, if the stored address information is associated with a second communication system (3006, 3007, 3008) that is different from the first communication system and that is capable of preventing transmission of image data to an inappropriate address. input means configured to input image data; transmission means (2010,2050) configured to transmit the image data input by the input means and be capable of executing a transmission process using any of a plurality of communication systems (3006, 3007, 3008); storage means configured to store address information which is used for identifying an address to which the transmission means (2010, 2050) transmits the image data and associated with any of the plurality of communication systems; reception means configured to receive a transmission instruction to cause the transmission means (2010, 2050) to transmit the image data input by the input means based on the address information stored in the storage means; and control means configured to control the transmission means (2010, 2050) to transmit the image data input by the input means in response to the reception of the transmission instruction, based on the address information stored in the storage means, and using the communication system (3006, 3007, 3008) associated with the address information; wherein the communication apparatus is configured to delete from the storage means the stored address information, after the transmission instruction is received by the reception means and the transmission process according to the transmission instruction is ended, if the stored address information is associated with a first communication system (3006, 3007, 3008); and characterized in that the communication apparatus is configured so that the storage means keeps storing the stored address information, after the transmission instruction is received by the reception means and the transmission process according to the transmission instruction is ended, if the stored address information is associated with a second communication system (3006, 3007, 3008) that is different from the first communication system and that is capable of preventing transmission of image data to an inappropriate address.