The National Cybersecurity Center (CNCS) has just presented a new recommendation regarding parked domains. You can see it here (only in portuguese).

A parked domain is a domain that is not associated with sending e-mail, which, without proper security measures, can be used relatively easily to forge e-mail addresses (email spoofing) and in sending phishing messages.

Technical Recommendation 01/2020 of the CNCS describes a set of good practices that should be adopted with this type of domains, thus contributing to prevent its misuse.