Techniques for reliable messaging for an intermediary in a network communication environment

The present disclosure relates generally to techniques for improving reliability of message communications. In certain embodiments, techniques are described for facilitating reliable communication of messages between a source (e.g., a client system) and a destination (e.g., a target system) via an intermediary communication handler system. In certain embodiments, a message can include a request to be communicated to a destination for a target service. An intermediary communication handler system can store information indicative of the delivery status for a message to ensure reliable communication. The information indicative of the delivery status for a message can be managed in association with a unique identifier corresponding to the message. The information indicative of the delivery status for a message may also be used to determine whether to retry communication of a message in satisfaction of reliability parameters (e.g., QoS criteria) specified for a communication protocol used for communication of the message.