1. A computer-implemented method for transferring data between computers, wherein a computer has a central processing unit (CPU) for processing instructions and memory for storing data, the computer-implemented method comprising the steps of: receiving a request message at a receiving computer from an originating computer, wherein the request message is addressed to a unique messaging identifier (UMI) that is uniquely associated with a user of the receiving computer and thereby specifies a receiving user for purposes of electronic messaging, wherein the request message is addressed from a UMI that is uniquely associated with a user of the originating computer and thereby specifies an originating user for purposes of electronic messaging, and wherein the request message includes a data directive that requests a retrieval of data from a computer that is used by the receiving user to a computer that is used by the originating user and/or requests a receipt of data from a computer that is used by the originating user to a computer that is used by the receiving user; automatically processing, at the receiving computer, the request message to determine access privileges for the originating user with respect to access privileges that have been specified by the receiving user; automatically accessing, by the receiving computer, a set of one or more datastores in order to read and/or write data in accordance with the determined access privileges and the data directive, wherein the set of one or more datastores are stored on one or more direct access storage devices at the receiving computer and/or on one or more remote storage devices; and automatically generating, by the receiving computer, one or more new request messages that are addressed to one or more UMIs in a set of UMIs that are uniquely associated with a set of users, wherein the set of UMIs has been specified by the receiving user, and wherein each of the one or more new request messages includes the data directive.