I’m on MacOS with the Mail app. Previously, I could tap on Mailbutler icon in the upper right corner of my computer, and see all the followup reminders I had. Pretty useful in case I’ve missed some reminders. I no longer see these features: where can I see the mails that I need to followup?
At this point, you can see all of your pending tasks either in the Dashboard or in the Sidebar feature of Mailbutler. Naturally, you can also set up follow up reminders so that you receive a notification if the task is not completed by the set time. For more in formation, please see this article: