Request for comments about the next Cozy architecture

How will be sent the system emails? The "Send Email" worker states that Cozy will contact the SMTP server to send the email. Will the SMTP configuration be part of the Email app (not a good idea in my opinion), will it have to be set up manually via Postfix for the self-hosted (ok), or even better, could the SMTP configuration be part of the "Settings" service?