Hi- I was in touch with AC support team in relation to this question and she confirms that we can still send one on one emails after contacts are unsubscribed. One on one emails are not emails like campaigns. They are directed toward just one person and do not have an unsubscribe link. You cannot send one on one emails in bulk, which limits the potential of abuse.
I just want to double-check if this is stated in the law and is it correct?
Thanks!