Use Outlook’s Task List
This little-known method can surprise even the pros !
Use Outlook’s Task List
Some emails don’t require an immediate response, but they do need to be handled before the time you have scheduled to review items in your to-do folder with a reminder. These items can still be moved to your to-do folder so they’re not clogging your inbox.
1- Drag the email and drop it on Outlook’s task list icon.

2- Add a due date and set a date and time to receive a reminder. Save the task.
3- You can view it in to do list

4- If you set a reminder, the task will pop up like a meeting reminder at the specified time.
Once the task is complete, mark it as complete to remove the task from your to-do list.