Multiple listeners on same interface?

Sure, but need to be done manually via /etc/pmg/templates and in that case master.cf. But why do you want to do, Port 587 is submission and PMG is not meant as direct outgoing mail server with auth on the server, just to relay your outgoing mail server with auth to the internet by filtering outgoing mails for spam and viruses.
 
Sure, but need to be done manually via /etc/pmg/templates and in that case master.cf. But why do you want to do, Port 587 is submission and PMG is not meant as direct outgoing mail server with auth on the server, just to relay your outgoing mail server with auth to the internet by filtering outgoing mails for spam and viruses.
Yeah I know but my current mail server performs authentication on port 587 through certificate.
Is it possible to replicate this in Proxmox?