Have 2 ports (25 and 587) listening for SMTP Inbound with STARTTLS

I have Domino 9.0.1 FP5. I need to have 2 ports listening for incoming SMTP connections: 25 with STARTTLS to receive email, and 587 with STARTTLS to receive submissions (MSA). The general idea is that port 25 should listen only to anonymous connections, so only for incoming email, and 587 only with authentication, to use for email submission, when our users want to send emails using our servers.

I the server configuration document, Ports → Internet Ports → Mail → SMTP Inbound, I can configure only 1 port to use with STARTTLS (the top one). I don’t intend to use the second one (SSL/TLS), because I want STARTTLS.

So, for now, I have only the port 25 enable, accepting Anonymous and Authenticated connections, and have setup our firewall so port 25 is mapped to port 25 internally, and port 587 is mapped to port 25 internally too. So, incoming emails entering through port 25 get to Domino using that port, and submissions (which use port 587) are also getting to Domino at port 25.

Does anyone knows how to configure Domino to listen at 2 ports for incoming SMTP connections with STARTTLS, like the top one at the server configuration document?
→ 25 with STARTTLS only anonymous, only to receive incoming email
→ 587 with STARTTLS, only authenticated users, to do submission (relay)

Thanks!

Subject: UP

Anyone? Is this possible in 1 instance of Domino? Another idea would be to have 1 server of the cluster to listen at port 25 (anonymous), and another one listen at port 587 (auth only)…