Under the present invention, a central system in communication with a central directory is provided. The central system also communicates with one or more ancillary systems that each communicate with an ancillary storage unit. User account information is initially stored in the central directory according to unique identifiers. When a triggering event occurs (e.g., when he/she attempts to access an ancillary system, or when he/she is listed as an intended recipient of an electronic mailing message), the user's account information will be located within the central directory according to his/her unique identifier. Upon location, the account information is automatically communicated to the appropriate ancillary storage unit. Thus, the present invention provides "just in-time" synchronization of account information between the central directory and the ancillary storage unit.