Update a workspace's email/marketing settings. Most importantly, this sets the marketing (business) address, which is the workspace-wide prerequisite for creating broadcasts and workflow send-email steps, and for sending broadcasts. When an address is supplied it is validated for completeness, so a 422 here means marketing-email creation and sending remain blocked. A workspace that has never configured its email settings has no persisted record yet; the first PUT builds and persists it, so it succeeds rather than returning a 404.
See the Business mailing address prerequisite in the Emails Skill for the exact body to send.