Please move this discussion to Products for a more prompt response.
If all members of the smart campaign are in the wait step between the emails, just remove the second send email from the flow. Once all people are out of the wait step, they will simply finish the flow and will not be sent the other email. If you remove the wait step, those already in the wait step will continue to wait the original duration. I would remove the second email flow step first.
Thanks. will move it.
I had no idea that you can play with the flow after the campaign was already activated. good to know!