Save the sent email as a template. Navigate to the scheduled email originally sent and click "Save as Template."
Set up your segment
Navigate to Contacts > Segments > Create a Segment
Add smart rule > Add a condition > Email Interaction > Has Interacted > Sent > Specific email > Select the sent email from the dropdown
Add a 2nd condition > Email Interaction > Has not interacted > Opened > Specific email > Select the sent email from the dropdown!
Create new scheduled email
Navigate to Calendar > Create new > Scheduled Email
Schedule your email for the date you'd like to send
Design this email > Select your template
In the email details, you'll select your Recipients. Choose the segment you created!
Save as ready to be sent!