Multiple Smarthosts for Outgoing Mail

Is there a way to configure multiple smarthosts?
not via the GUI - have not checked explicitly but would assume that you can achieve that by modifying the postfix config (I think starting with `man 5 transport` should help in finding the necessary options)

If you adapt the postfix config in PMG you need to do so via the templateing system:
https://pmg.proxmox.com/pmg-docs/pmg-admin-guide.html#pmgconfig_template_engine

do you want to send the mails out in a round-robin fashion? or how do you want to decide which mail goes out where?

I hope this helps!