Hotmail Exchange absent from SMTP Server List

2025 MBP running Sequoia 15.5. Added Hotmail Exchange internet account. Connection Doctor shows green, but OS Mail can only receive emails and cannot send them. It returns the message that the email address was rejected by the server p14-smtp.mail.me.com and the server response was: From address is not one of your addresses. If I try to edit the SMTP Server List there is no Exchange or Hotmail server to select.

I have verified that the account and server settings on the MBP are identical to those on the Mac Studio, which works flawlessly. Is there a glitch in the way MS Hotmail sets up on the MBP? Cust Svc has been unable to figure it out. I'd be grateful to be able to use my primary email on my new MBP!

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