The present disclosure is directed to a technique for reduction of latency in network traffic data transmissions. The system parses an online document to determine a messaging identifier used to communicate over an asynchronous network-based communication channel with a content provider device. The system assembles a first instance of the online content item with the messaging identifier. An intermediary appliance located on the asynchronous network-based communication channel in between the first computing device and the content provider device intercepts data packets including the electronic message The system determines a quality of the asynchronous network-based communication channel. The system blocks insertion of the messaging identifier in a second instance of the online content item prior to transmission of the second instance of the online content item to a second computing device to reduce latency by preventing additional messages from being sent to the messaging identifier.