The invention discloses a semi-permanent address based message sending method. According to the semi-permanent address based message sending method, an RCode (Residence Code) of target equipment of an account is obtained firstly, then messages are sent to the target equipment directly, and message detour is reduced. The invention also discloses a residence identification method which is used for obtaining the RCode of the target equipment of the account. The invention also discloses a SPAddr (Service Provider Address) based message sending method which is used for directly sending messages to the target equipment of the account. The invention also discloses a SPEmailAddr (Service Provider Email Address) based message sending method. The invention also discloses a residence identification method which is used for directly obtaining a new RCode of the SPEmailAddr. The invention also discloses an HSvr (Home Server) which can eliminate bottleneck factors and reduce message detour. The invention also discloses a message processing method which is used for processing messages from other HSvrs. The invention also discloses a residence identification message processing method. The invention also discloses a RIDSvr (Residence Identification Server) which can achieve load sharing.