I can confirm this. I verified the license from the link on the email screenshot (had to type it manually) and it says the license of Prism Sentinel N.V. is valid, just the URL is not verified!

However, I don't understand why they didn't fix the link in the footer and update their website info with their license provider although you notified them about it more than a month ago! It should be a priority and it doesn't take much time. A regular user should be able to verify the validity of a license at the click of a button and not make a thorough research. (just my two sats)