Removing "recent" recipients from the autofill list in Apple Mail on iPhone

In Apple Mail on my iPhone, how do I delete contacts that pop up when I start typing a naming in the To: field? This is what one would think of as the Previous Recipients list. I cannot find a place on the iPhone where such a list is stored, and suggestions and articles that I've read online talk about tapping a Remove From Recents button that never appears in my interface, or if I can get it to appear, it does nothing.

Just to sum up my approach, I start typing in the To: field, and I see a scrolling list of possible recipients. Some of these are multiple recipients, with a right-facing arrow. I tap that arrow, and it turns to a down-facing arrow and there are the individual recipients, each with a little "i" at the right. I tap that "i" and I see a sort of contact card for that recipient, but there is no option to Remove From Recents.

If I tap the actual name so that it appears in the To: field, I can then tap _that_ to see a sort of contact card that _does_ have a Remove From Recents button! But tapping it seems to have no effect; the same person keeps popping up in various combinations of addressees.

The people I want to get rid of do _not_ appear in the Contacts app. There seems to be a list of "recent recipients" that is private to Mail itself, but I can't find a way to access it and edit it. (The people are not in the "recent recipients" on my computer; just on my iPhone and my iPad. I have no idea what sort of sharing it could be where the same list is being used on my i-Devices but not my computer.)