toa@xn--ngpukapuka-vfb.nz writes:
Today I received a message in my toa@ngāpukapuka.nz mailbox from a sender through MailChimp!
IIRC at least four other companies in the same sector are too, namely Elastic Email, Mailgun, Return Path and SMTP2Go. (Some of those would disagree that they are in the same sector — there's email and email.) JFYI, the message you sent isn't an EAI message, it's a legacy message that happened to use "xn--" in the domain. If you look at the Received fields, you can see it was transmitted by the initial sender via "smtp", not one of the protocol types specified in RFC 6531 section 4.3. For this reason, the top line of this message is actually an accurate rendering of the address according to your instructions (which I expect do not match your intention). Arnt