Hey Martina,

For your flow filter, you should have ‘Placed Order Zero Times Over All Time’ to keep anyone who has ordered before from getting these.

For the messages, you can add in conditional split in your flow after your delays to check if someone has opened the message. It’ll look something like so - 

 

Tricky thing is that the messages may not appear in the drop-down until it starts sending. The work-around is that you should do ‘where’ - ‘Subject’ and plug in the subject line instead for the message. You’ll then repeat this split before each message to cross-check that they didn’t open a certain message before.

You could even do ‘Flow’ instead of ‘Message’ and apply this as a Flow Filter to the entire flow where it checks if someone opens ANY of the messages inside of the flow and then pulls them out. A couple ways to make this happen.

Hope this helps!