We use a hypersend agent. It had not occurred to me to use the http-client connection, but I would be interested to know if this is a viable option as well. I am going to do some testing of it and will monitor this thread.
I received an answer from Jeff Beamsley @ Hilgraeve. The Cloverleaf HTTP-Client function is not an option. You must use their Hypersend client to send/receive data from the Hypersend customer’s HTTPS server.