Is it possible to make several smtp servers available on one white IP?

Question

SMTP

There is an HTTP/HTTPS proxy, which allows, depending on the domain name, according to the rules, to redirect traffic to different internal IPs through one external IP. Is it possible to do this for SMTP traffic?

Answer 1

Option 2:
1. You can use the already installed Exchange and Receive Connector of the Internal Relay type.
2. Or use the frontend (Postfix for example - smtp with Mikrotik is forwarded to it).
Which will be the router for your cloud of domains.