Abstract: A method, system and server for processing messages sent from a client in a network are provided. The method comprises: for a message for a conversation to be transmitted from a client associated with a first user account of a plurality of user accounts associated with the network to a set of user accounts of the plurality of user accounts, upon activation of a command to send the message, sending to the set of user accounts a request message requesting acceptance of the conversation; receiving replies from the set of user accounts to the request message; and sending the message for the conversation to a first subset of accounts associated with the set of user accounts that generated an acceptance message for the request message and updating a message log associated with the conversation to indicate that the first subset of accounts has accepted the conversation as participants in the conversation. A method, system and server for message archiving are also provided.