Unity Connection SMTP Domain

[Gazzbut]

Currently we are using our main email domain in Unity Connection but I have been trying to setup smtp notifications and I get an error saying the specified doamin cannot be the same as connections. We dont use viewmail in outlook or anything else that would send smtp to unity so am I right in saying the we dont need to setup connection as an smtp server and that the smart host is not linked to the smtp config as that is for relaying messages i.e outgoing rather than receiving smtp?

Thanks!