1. A document retrieving and delivering method: comprising the steps of: registering retrieval conditions inputted from a plurality of users; and retrieving, from texts of document information inputted, texts satisfying the retrieval conditions and delivering the texts to the users associated therewith, wherein the retrieval and delivery step includes the steps of: calculating similarity of the text for the retrieval condition; determining according to the similarity whether or not the retrieval condition is satisfied; and delivering, when the retrieval condition is satisfied, the text to the user corresponding to the retrieval condition.