I've had many conversations about email recently. I try very carefully to leave my inbox empty at the end of a "work" day. It doesn't always work especially when I travel but it's a regular thing when I'm at the home office. So how do I do it.
1. Answer the email.
2. File it under - senders name, temporary or hot topic.
3. Use my favorite button of all time Delete
My feeling is that the favorite button for most in the work world is CC. The American mentality is to save every email ever received and CC everyone. In other words Cover My Ass. This system does only one thing, clog up your email. Next time you think CC think don't. Next time you think "I should file this and you don't know where it should go, hit delete." You will learn to love my favorite button.
And if you happen to Delete a really, really important email I can almost guarantee it will either come back to you in a CC or you can simply ask the person you are working with, they saved it to cover their ass.