System and method enable users of instant messager to retrieve sent messages

A system and a method enable a user of an Instant Messager (IM) to retrieve the sent messages temporarily stored in the server. The invention providing an operation interface at the client and an retrieve module at the server offers the users to send a retrieve command through the operation interface for retrieving the stored messages in the server. The retrieve module deletes the messages assigned by the retrieve command. Thus, it solves the problem of being incapable of deleting the messages temporarily stored in the server in the IM communication network. The invention can satisfy the diverse requirements of the IM users.