Perhaps you’ve been signing up for a lot of different mailing lists. Maybe your friends are forwarding you things you don’t want to read straight away (if at all).
Why not set up your email program so that these messages are automatically sent to an email folder that you check less frequently? There’s no reason to interrupt your day to read messages that have little or no immediate benefit – why not spend a larger block of time less frequently, when you’re looking for a distraction or some mental down-time?
Here’s a useful list of 5 Types of Emails You Should be Automatically Filtering.