Method for processing deferred message

An instant message (IM) server for processing deferred messages, applicable under Session Initiated Protocol (SIP) and Instant Message and Presence Leveraging Extensions (SIMPLE), said IM server comprising a storage entity configured to store the deferred messages, a notification entity configured to notify the deferred messages and a retrieving entity configured to retrieve the deferred messages, wherein

• the storage entity configured to store the deferred messages to be sent to a user in a case that the user pre-requests for storing the deferred messages;
• where the deferred messages comprise meta-data and content, and the meta-data and content are stored separately in different storage entities in the step of storing the deferred messages, the meta-data is stored in an IM Extensible Markup Language Document Management Server entity (IM XDMS entity) and the content is stored in a deferred message content storage entity;
• the notification entity configured to determine there are deferred messages for the user stored in the IM server associated with a client of the user when the user gets online, and sending a deferred message notification to the client of the user;
• and
• the retrieving entity configured to send the deferred messages to the client by the IM server in response to a request from the client for retrieving the deferred messages after the client receives the deferred message notification.