Email setup for app functionality

Question

I am working on an app, and have setup a ******@domain.com email address with a Microsoft365 subscription. The email is intended to send emails from the server to the user during registration, with the registration code, email confirmation, etc.

Unfortunately, I am not able to set it up.

The domain is from GoDaddy, but DNS hosted by Microsoft365.

Based on research, I have updated the SPF record on the DNS to add the IP for the server, I have added dual factor authentication, etc. Did everything i could find to do on the internet. Nothing works.

Does anyone have a step by step for how to get this done? Important is also what is the setup needed for it to work so i can make sure it is all back to what is was, and I have not made any changes in my multiple attempts that jeopardize the security of all other emails.

Disabling the security defaults makes it work. Not something I would want to leave disabled, but at least maybe an indication?