Chuck
NewTek Social Media
Did you try adding orange.fr to the e.g. white list?
http://www.barracudacentral.org/lookups/lookup-reputation
https://www.google.com/search?q=barracuda+disable+blacklist+orange.fr
I don't know what IT did exactly, but after some investigation into what they might be able to do, they did something they referred to as a "private exception" and we can now receive emails from Denis. Many thanks to IT and to Steve Bowie for working with them on this.