Reminders are a good thing.
Thats what nudges are for in Gmail.
You may forget to answer an email and never get around to replying.
What nudges does is that it brings back that email to remind you.
To access controls, tap on the cogwheel at the top right and choose All controls.
Once youre in prefs, you will see various tabs at the top.
Scroll down and look for the Nudges option.
you might also choose to only have one enabled if that works better for you.
Once the Gmail app is open, tap on the three-lined menu and swipe down to parameters.
Once youre in configs, tap on the account where you want to make the changes.
Swipe down a little more until you come across the Nudges option.
Tap on it and check or uncheck the boxes for both or one of the listed options.