Important Message missing from Hub, and Message App

Last night sent an important message to a doctor via my icloud email account to [email protected] from my iMac.

Checked on my Keyone last night late and no response.

However, this morning I checked the Messages app on the iMac and there was a response from the doctor right after I sent the email.

If I had not checked the message app on the iMac, I would have missed this.

This message has not shown up on my Keyone in the Hub, or the Message APP.

Why not, the doctor would have answered from their iPhone to my iCloud email.

I would think it would at least show up in the HUB under my iCloud email account.

What is going on here! Why did the message not show up in my notification, HUB, or Messages.
Comments?

Sounds like your Mac assumed it was an iMessage. Are the numbers/emails you set in Messages on your Mac the same as you use on your phone? - https://www.imore.com/how-set-messages-your-mac