How and why we built Masked Email with JMAP, an open API standard

I wish this supported fastmail subdomains, not just the main domain. Would be nice to have e.g. correct.horse.battery@mask.example.com instead of correct.horse.battery@example.com

Why only Fastmail? I would say Hey.com is pretty privacy-oriented as well.

Well, based solely upon the number of times JMAP is mentioned in TFA, I'd guess it's because Fastmail is likely the only(?) provider who uses it

I _suspect_ this is whatever the marketing equivalent of a "backronym" is: in that they decided to partner with Fastmail, then Fastmail was all "JMAP or GTFO", and then a blog post resulted talking about how awesome JMAP is