Would be great to have a way to choose and change if needed the different IP addresses for bounce messages and outgoing SMTP traffic on the mailserver role.
In my legacy H-Sphere I'm able to choose the bounce IP, this is useful for avoiding be included in the blacklists, service IP, this is usually main IP that answers to incoming packets and outgoing IP which is used as a source ip on all other SMTP sessions originated on the server, this is useful when your server was caught by some blacklist, you found and resolved the problem, you can change IP to allow the traffic while dispute with blacklist administration for removal.