If you're noticing the the Polymail app is becoming unresponsive randomly and you're having to Force Quit the application, it may be the result of something going wrong in your Polymail Application Support Folder. 

By deleting the Polymail Application Support folder, you'll be able to force the Polymail App to recreate a new application folder and resolve anything that may be going wrong. 

To start a new Polymail Application Support folder, we'd recommend you follow these steps:

  • Hard close the Polymail app
  • Uninstall the Polymail app
  • Opening to Finder.app
  • Using the shortcut CMD + Shift + G
  • Type in ~/Library/Application Support
  • Delete/move the Polymail folder in the Application Support Folder to trash
  • Reinstall a fresh copy of Polymail by downloading it from here.

Don't worry. This only removes Polymail's Application Support. It doesn't effect any other application or any files related to your macOS. Once you have installed a fresh copy of the application, a new Polymail Application Support folder will be created.