I have in my Express server
Express
userbase = {\'Fitz\': \'84Iw3MNEIMaed0GoAAAD\'}; //Exapmle user to receive message and associated socket id //S
Do you have users join a namespace on connection?
socket.join(userbase[data_from_client.to_user]); //'84Iw3MNEIMaed0GoAAAD'
You can try:
socket.in(userbase[data_from_client.to_user]).emit('get_msg', {msg:data_server.msg});