Configure SMTP with relay server

Is there any way to deploy user management with SMTP with a mail relay?

I need to set it up without username or password as we have internal mail relay.

Not currently, the only workaround is to run something like GitHub - maildev/maildev: SMTP Server + Web Interface for viewing and testing emails during development. or GitHub - mailhog/MailHog: Web and API based SMTP testing with auto forwarding.

You set it up with a basic user/pass and set the upstream to your relay without auth. Then connect n8n to e.g. maildev:1025

Or of course add a user account on your mail relay…