Email setup is two things: verifying a domain to send from, then switching on the automated flows that run off it.
How do I set it up?
Add the domain you want to send from and verify it.
Under Automated flows, turn on the flows you want running.
Why do I have to verify a domain?
Mail sent from an unverified domain lands in spam. Verifying proves the domain is yours, so messages arrive from your brand rather than from a generic sender.
What's next
Flows and their performance live under Email, and the individual flows under Flows. Sending settings are in Email setup.
Next, set your brand voice - it shapes what these emails say.