Emails sent from iCloud+ (custom domain) to various Microsoft domains (outlook.com, hotmail.com, msn.com) keep bouncing with “please contact your internet service provider since part of their network is on our block list”. Of course, the “internet service provider” is a red-herring. It’s email service provider; it’s Apple.
You would think the giants have their relationships figured out, eh? Apparently not. This only happens with Microsoft, though, no one else.
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