4. The apparatus of claim 3 , wherein, when the corresponding number of the one contact is added to the conversational information associated with the one contact, the management unit is further configured to incorporate the conversational message associated with the corresponding number, before the corresponding number is added, into the single conversational content with the one contact by processing the conversational information associated with the corresponding number before the corresponding number is added.
4. The apparatus of claim 3 , wherein, when the corresponding number of the one contact is added to the conversational information associated with the one contact, the management unit is further configured to incorporate the conversational message associated with the corresponding number, before the corresponding number is added, into the single conversational content with the one contact by processing the conversational information associated with the corresponding number before the corresponding number is added. 5. The apparatus of claim 4 , wherein the management unit is further configured to set the conversational message associated with the corresponding number which is deleted or replaced in the single conversational content associated with the one contact to be in a non-reply-able status.