Hi Ryan,
If a lead does not qualify for the campaign, they will not receive any content that cast.
A workaround to this would be to only have Member of Engagement Program =True filter in the Smart Campaign (everyone will qualify for this campaign). In the flow, you could set up choices. To use your example, you could have a choice like: If Email Address contains google.com, then send Email #1. Your default choice could be to send the email (call it Email #2) that will go out the following cast.
The next week, everyone who received Email #1 will continue in the stream and receive Email #2 and everyone who received Email #2 will skip a piece of content and receive Email #3.
Will