Continue email draft on another device

Okay, I could have sworn this could be done - I started composing an email on my iPhone, well into it, realized it was going to be of some length, and didn't want to continue typing it on my little iPhone screen, but rather my iPad, or even my Mac, so saved it as a draft, thinking that it being done with my iCloud email account, it would naturally just handoff/sync to my iPad, and even my Mac... but alas, no.

Why is it not? Apple claims that this handoff feature is just for things like this, and I was even composing it on my iCloud email account, but nothing on the other two devices. Handoff is turned on on all three, all three are on the same wifi network, signed into the same iCloud account, even turned on bluetooth on all three as I read somewhere that was necessary, but the draft is not showing up on either my iPad or Mac.

Why is this not working?

Advice. Suggestions.

Thank you for your time, and any help you may provide

JPH