I don't like to share my email address if at all possible. I use Hide My Email to create disposable emails for every service.
I'm unable to verify the 'hide my' email that I used. No confirmation email is anywhere in my (real, actual account).
I had to use a throwaway email account (like, a real one), just to post on the message board. And even then, the message barely arrived.
Be careful with this message
The sender hasn't authenticated this message so Gmail can't verify that it actually came from them. Avoid clicking links, downloading attachments, or replying with personal information.
Maybe once Hubitat corrects their email settings so they don't get flagged by Google, the emails will arrive and won't get stopped by either iCloud or Google before they show up.