Microsoft has been ab-using IPv4 in context of Mail to target-specific hinder competition, so they have a lot of reasons to not support IPv6 well where this isn

Microsoft has been ab-using IPv4 in context of Mail to target-specific hinder competition, so they have a lot of reasons to not support IPv6 well where this isn't as much doable. (For example Microsoft has blocked whole IPv4 ranges of cloud providers (i.e. Microsoft Azure competition) for E-Mail, supposedly because of abuse. But all cloud providers are used by people "producing bad mails" and somehow only small to mid-sized ones are blacklisted while e.g. Google or Amazon are not and to be clear that had not been cloud providers in some arbitrary small country but e.g. the EU).