Have a look at the Chat example. If I recall correctly, each time a user enters/leaves the chat a corresponding message is sent to all the participants.
client status can only be handled by the Broker. Look for a Broker who has SDK support than you can do customisation over callbacks. eg. get connects, disconnects send email execute custom code etc.
client status can only be handled by the Broker. Look for a Broker who has SDK support than you can do customisation over callbacks. eg. get connects, disconnects send email execute custom code etc.