Every alert, filterable, beyond what the bell shows.
The bell in the header shows the most recent alerts. The Mail is the full history, on its Messages tab; the Where they go tab is where you route them.
Filters
All, Unread, Clients, Flows, Billing, Announcements. Mark all as read clears the count; when there is nothing left it says All caught up.
Deleting mail
Delete removes one message. Clear all deletes every message after a confirmation, and cannot be undone.
What arrives here
Clients: a client went offline, a start was refused or kept failing, or a dedicated IP stopped working. The one worth watching: it is how you find out something stopped without staring at the Clients page.
Flows: messages your flows send, flow errors, and updates on flow requests.
Billing: billing alerts and purchase receipts.
Announcements: product news.
A client-status notification links straight to the client it is about, so you land on its console rather than a list.
Flows can write here too
The notify action sends a message from a flow to you, reaching the mail plus every channel you have switched on:
Use it for things you want to know about. For tracing a flow step by step, use log instead, which stays in the client's console.
Choosing what you get
Which notifications reach you, and where, is set per category and per channel. See channels.