Domain mapping - Dedicated IP question

Alright guys and gals... got a new one for ya

I'm at Media Temple, and they don't give dedicated IP addresses without having an SSL certificate (for their Grid Hosting). Even then, when they give out that Dedicated IP with an SSL, it's only for INCOMING connections, not outgoing (outgoing connections can be sent from any IP on the grid).

My question is, for this plugin to function, only Incoming is necessary right?