A system and method for managing output such as printing, faxing, and e-mail over various types of computer networks. In one aspect, the system and method provides for accessing print and/or document resources located on private networks behind firewalls. A pass-through communication link is established between system components located on opposing sides of a firewall. A system-served user-interface enables users to select source data and an output device on which the source data are to be printed, either or both of which may reside behind the firewall. The source data are then retrieved and forwarded to a print service, which renders output image data corresponding to the source data and the selected output device. The output image data are then submitted to the output device to be physically rendered. Access to private resources is provided by the pass-through communication link. The system also enables documents to be printed by reference.