Settings → Mail lists outgoing mail configurations. Columns: Driver (SMTP or RESEND), From, Default, Purpose, masked Credentials.
Fields
Driver, From Address, From Name, Purpose (optional, up to one configuration per purpose, for example free trials or support), Set as Default, and for SMTP host, port (587), TLS, username, password; for Resend the API key. Passwords and keys are never shown again; leaving them blank keeps the saved value.
Buttons
Test Send (5 a minute per person), Edit Config, Delete Config. The last global default cannot be deleted. Errors appear as toasts.
Mail settings need the credentials permission; unlike mailboxes they have no plan gate.