Yes, if it is done correctly. I will review that material tomorrow and see what (if anything) is outdated in it.
It sounds though that you are sending with a user that is not authorized on the MiaB? I usually suggest that the sending email address is the same as the email user on MiaB.
“It sounds though that you are sending with a user that is not authorized on the MiaB?”
That’s what’s confusing about it - I set it all up as per the instructions with a MiaB user. But the error seems to suggest that’s not actually carrying through when sending, or similar.