We're sorry you're experiencing this problem. 😕 This can sometimes happen when there's an issue with your Polymail preferences. 

Going in and removing your Polymail Preferences files will force Polymail to recreate it and should resolve the problem! 🎉

We'd recommend doing the following:

• Close the Polymail macOS app

• Open to Finder.app

• Use the keyboard shortcut CMD + Shift + G

• Type in "~/Library/Preferences/ctrlla.Polymail.plist" 

• Delete the files with the name "ctrlla.Polymail.plist,"" io.polymail.osx.helper.plist," and io.polymail.osx.plist

• Restart Polymail macOS app

Not to worry! This only removes Polymail's Preferences file. It doesn't effect any other application or any files related to your macOS.