Hello,
To use ProxMox PMG as a SmartHost it's really very simple.
You have to configure as follows:
On the ProxMox PMG side:
Configuration -- Mail Proxy -- Networks (tab), you have to add the IP addresses of the mail server that are authorized to send emails. So in your case the IP addresses of your Enhance servers.
Configuration -- Mail Proxy -- DKIM (tab), you have to activate dkim, create a selector and say "Sign all Outgoing Mail" on Yes. No need to put a domain in the "Sign Domains" list because we just said above to sign all outgoing mails!
Then you can see the generated DKIM key that will have to be added in all the domains that will send emails via ProxMox PMG as a SmartHost!
DO NOT FORGET TO CREATE YOUR PROXMOX PMG REVERSE DNS!
On the Enhance side:
Either at the general settings level in:
Settings -- Email -- Smart Host Settings:
Only the following values:
Hostname: URL of your PROXMOX PMG!
Port: 26
The rest do not put anything! Click on save!
Same if managed at the mail server level directly!
