Cannot sent email. iCloud Keychain issue???

I cannot send email from any browser nor any mail app. I tried on multiple devices, including my Apple devices, windows devices, different browsers, different ISPs, different cellular connections. No dice. I can receive email. I cannot send.

This happened on November 9th and miraculously corrected itself. Now it has happened again.

I have wiped my MacBook Pro, logged in and out of every device, deleted all system preferences, even reinstalled clean MacOS Monterrey. Nothing.

I have never been so frustrated as a customer after so many years. I have spent hours on the phone with your technicians. No one can figure it out.

Closest we got to a solution was my iPhones mail app would finally send email, but only temporarily. Strangely on the same device with the same network connection, when going into Safari and on iCloud.com, I could not send email still, yet in the app I could.

There is seriously something screwy going on here. And it is creating **** for me and my correspondences. I operate a web store and my contact has been my iCloud email for a long time. Please help. Don't give me the go to a Genius Bar crap either please. This is well above them and most of your tech support specialist. Your engineers could not help me either. Please for the love of email I need a solution now!