Keyboard shortcut for "Find in mailbox"

The Problem

I’d like to search within all my mailboxes in a quick way.

Proposed Solution

Using keyboard shortcut CMD+K to search within all mailboxes. This should be also shown within the menu bar as documentation.

Context

There’s already the shortcut CMD+F to search within a thread which can’t be reused. CMD+K is a common shortcut to search everywhere which is also used by Slack and other tools.