Message sending method, apparatus, and system, and server

An open platform server, comprising:

• one or more processors;
• memory;
• and
• a plurality of programs stored in the memory and to be executed by the one or more processors, the plurality of programs including a social networking application enabling message exchanges between user accounts that, when executed by the one or more processors, causes the open platform server to perform a plurality of operations including:
• receiving a group-sending interface invocation request sent by a target user account, the group-sending interface invocation request carrying a to-be-sent message and at least one group identifier associated with the target user account, a follower group corresponding to each group identifier comprising a user account of at least one follower of the target user account, and the target user account being a user account that a service provider applies for to the social networking application;
• and
• invoking, according to the group-sending interface invocation request, a message group-sending interface to send the message to a client terminal corresponding to a user account in a follower group corresponding to each of the at least one group identifier.