At a gateway within a network, a message containing content is received. The message conforms to a protocol that specifies a format of the content, the message having been sent from a server outside the network to a client within the network. The message is routed from the gateway to the client. The message is analyzed to determine whether the content is static. Depending on a result of the analyzing, the content is selectively caused to be stored in the format specified by the protocol in a cache within the network.