1. A method to determine automatically a user specific relevance score of a message within a messaging system in a client-server environment, the message being provided with message specific meta-information, comprising: analyzing by means of an analyzing component of the client-server environment the meta-information of the message with respect to correlations of the message with other messages, wherein the message and the other messages are both contained within a message thread; recording and classifying the correlations between the message and the other messages within the message thread; deriving from such identified and classified correlations a message model reflecting the correlations of the message with the other messages, the messages being represented by accordingly linked nodes, wherein each node in the message model represents a corresponding one of the messages contained within the message thread and the sender and recipient of the corresponding message; monitoring by means of a monitoring component of the client-server environment how the message is processed; calculating by means of a calculating component a numerical relevance score for the message, the calculation using a user specific ranking scheme and being based on the message model and on the monitored processing; and assigning the calculated numerical relevance score by means of an assigning component of the client-server environment to the respective node representing the message within the message model.