Exactly. Mail to you goes to where ever your DNS MX record is pointing to (obviously in my case that is my home IP) and local delivery is configured how ever you choose to do local delivery. Sending is simply configured how ever smart relaying is configured on your MTA of choice. All mail sent from your MTA is sent directly to your smart relay and goes out to the world from there.

There is a trusted type of relationship between your MTA and the smart relay so the smart relay is not set up as an open relay. If your smart relay is an open relay, it may end up on blacklists as well, for different reasons than originating from a residential IP block.