Vicky,
Is this flow you are showing us in a Program that was placed into the Stream? If so, the lead will probably skip the intended email, but they will still go through the Program because they hadn't received that first Cast yet.
Engagements only know to skip content when the lead already received the content via the Engagement.
Hi Vicky, are you using programs or just single emails within your engagement programs? It looks like it might be programs, based on what you've shown above.
If you're using programs, I'd say the easiest way to exclude someone from that email would be to create an additional program status called Exclusion (or similar) and if they join the Engagement via the inbound program then they should be added to the exclusion status for the first program/email. By adding them to the program, Marketo will not send that content to them since they're already a member of the program.
If you're using single emails, the only way to prevent someone from receiving it is if they've already received the exact same email (regardless of whether or not it was in engagement, I believe). This means no cloning, or creating an email that looks the same -- Marketo doesn't know that it's the same. Otherwise, you might want to do separate streams within that engagement program.
Hi Dory Viscogliosi, when you add an exclusion status, how do you make sure Marketo actually excludes leads with that status in the email send program? What needs to be done in the background? Thanks!