A system and a method for managing mails and files are proposed, which are applied to a network environment e.g. Internet, allowing received mails or files to be classified and systematically stored in a database, according to receiver's group, mail subject, file name and type, and/or sender's address. This therefore allows an authorized user to efficiently search mails or files from the database in response to receiver's group, mail subject, file name and type, and/or sender's address provided by the user, so that the desired mails or files can be quickly retrieved.