I have dramatically simplified my Guaranteed Delivery which provides queuing and delivery of messages to a remote server, such as email, upload, influxdb writes etc.
I have extracted the delivery logic into a subflow so that it is now very easy to use. For example to use it for email the flow looks like this
To use for for an alternative application it is merely necessary to provide the delivery flow (the email node in this case) and logic to send back an OK or FAIL message into the subflow to tell it whether to move on to the next message or to wait for a configurable timeout and then try again. In the case of email it is particularly easy to determine success or failure as the email node is well behaved, it may be more complex in other applications.
Influxdb writes can be handled in the same way as email as a recent update to node-red-contrib-influxdb (0.5.4) has provided Complete and Catch capabilities.