A network file access appliance operates as a secure portal for network file access operations between client computer systems and network storage resources. The file access appliance terminates network file access transactions, identified by packet information including client system, mount point, and file request identifiers, between client systems and mount points supported by the access controller. A policy parser determines, based on the packet information, to selectively initiate network file access transactions between the access controller and network storage resources to enable completion of selected network file access transactions directed from the clients to the network file access appliance. The network file access transactions directed to the network storage resources are modified counterparts of policy selected client network file access transactions modified to reference mapped network storage resource mount points and support the secure transfer and storage of network file data.