Difference between 'Clear' and 'Trash' in iPhone 16 Mail App

This is Apple Intelligence enabled on an iPhone 15 Pro, iPhone 15 Pro Max, or iPhone 16, presumably.

This particular more-flag-trash-clear display is not documented anywhere obvious, but that mail message is categorized (by Apple Intelligence) as a primary or time-sensitive (clock) mail message, and as news, subscriptions and social updates (speech bubble). Selecting clear reportedly removes it as being time-sensitive.

The same place as the social update (speech bubble) icon is shown can alternatively show as a shopping cart meaning the message is interpreted as a transaction, or as a bullhorn meaning a promotion or sales deal.

I’m not sure how useful any of this Apple Intelligence stuff will be, given it seems quite confused about many of the contents of the mail messages locally. Looks like it’ll need probably some training too, like a spam filter.

If you don’t like the categories and the priorities mechanism available from Apple Intelligence in mail on iPhone, tap the three-dots icon in the upper right of the mail message list view and select the traditional view. That three-dots display:

There’s also some little explanatory “about” text included there, too. That “about” text:

What I can find for available documentation (not much) of this: Use Apple Intelligence in Mail on iPhone - Apple Support