In my workflows, using the concept written in 'Don't Check Your Email First Thing in the Morning', I tend to have a set time mid-morning and late in the day in which I clear my emails, creating an empty inbox. Anything I can answer immediately, I will do so. Using GTD principles, everything else that is not easily answered goes into the In-Tray to be analysed later to be planned for action.
I like that you can drag emails from Apple Mail to Good Task, but it would be great if there was a plugin for Apple Mail so that you can send an email to Apple Mail. This would be more efficient. Todoist and a number of other apps do this and so I would love to see this become one of the many great features!