Transmitter-receiver for electronic mail that provides convenience to a user receiving mail services from various mail service providers at different terminals and different places

A transmitter-receiver for transmitting and receiving mails to and from a user terminal by an electronic mail system, comprising:

• a plurality of mail spools for retaining mails transmitted from said user terminal, each of said mail spools having a spool number,
• wherein each mail in said mail spools is managed in accordance with said spool number and a mail number assigned to said mails;
• and
• a spool integration unit for integrating said plurality of mail spools and for making it possible to gain access to each of said mail by regarding said plurality of mail spools as a single spool,
• said spool integration unit including:
• means for determining, among said plurality of mail spools, any mail spools where a mail designated to be read out is stored,
• means for converting a reading command for reading out a mail from a single spool into a reading command for reading out a mail from each of said spools which have been determined by said means for determining,
• further means for determining whether or not plural mails retained in said plurality of mail spools have a same mail ID given by a transmitter, and
• means for assigning the same mail number to plural identical mails having the same mail ID.