K-9 Mail - Pushing mail only when interacting with app needed

With K-9 Mail, could you please advise if it is possible to have these mail fetching settings: 1) Polling every hour, both when interacting with the app and when running in the background. but also: 2) Pushing all folders only when interacting with the app, but not when the app is just running in the background. The reason for this is that I like push to update folders promptly when interacting with the app, but don't want to have unnecessary push connections open in the background. However, I still like to poll in the background to be notified of new messages periodically. I am using a Gmail IMAP account on a tablet running Android 5.0.1. I have read through the documentation and been through the settings but would just like clarification on the above points.