> You can in detail ask about ALL personal data that was used as an input for this decision, information about the ¨automated decision-making¨ (algorithm), and all personal data that resulted out of this process. https://gdpr.eu/article-15-right-of-access/

That is only true in specific cases of processing, as detailed by article 22: "a decision based solely on automated processing, including profiling, which produces legal effects concerning him or her or similarly significantly affects him or her".

In the case of a domain name used for email I think you could legitimately argue that the decision "significantly affected" you, but it's kind of undefined so far what the bar is for this criterion.