SMTP
Connect an SMTP server with a named organization connection, then pick that connection on SMTP and HITL SMTP nodes in Actionflow Studio.
SMTP
Add a named organization connection under Organization → Integrations → SMTP. Communication SMTP and HITL SMTP nodes pick that connection. Host, username, and password stay on the organization, not on the canvas.
Platform Human in the Loop Email uses ActionFlows Resend. It does not use this SMTP connection. Use HITL SMTP when mail must go through your server.