Assuming that you carry a device with Internet access with you all the time, you are probably getting bombed with all kind of notifications. These perpetual alerts manage to come with us no matter where we go or what we are doing, intermittently dragging our focus from one thing to another.
Let me tell you my daily email routine to minimize unnecessary email distractions. The main trick is to establish check points along the day (when you will be able to check for incoming email) and to filter email notifications so you do not get constant alerts while you are doing other things (I will explain you how to do this later).
I established two check points, the first one at noon (12:00) and the second one in the afternoon (18:00). This check two points are the only time I open my email and process my inbox —read, archive, delete, reply, and add to my to-do list any emails which require later action.
If I have the need to send an email out of this check points, I would either save a draft of it in my to-do list and send it in the next check point, or I would just send it anytime if it is an important matter.
The device I always bring with me is an iPhone, and [almost] all of my notifications are disabled. No badges. No alerts.
What happens when you are waiting for a “super important” email that makes you check your email every five minutes?
A few years ago, Apple added VIP contacts on iOS, as a way to whitelist the people of your address book you care about, and manage their notifications apart from those of non-VIP contacts. The system works the opposite way than spam filters do. Here, you select the contacts that really matter to you, customize the VIP, and switch off all other notifications.
Notifications can also be customized on a per-contact basis for other services as Messages, for instance, where you can deactivate the vibration or sound alert by default, then activate it individually for a given set of contacts.
This way, you will avoid undesired distractions when you need to be productive, and will still be notified of important incoming messages from the contacts you choose.
The same logic can be applied to any other service. You can selectively filter notifications for other apps in your device, impose yourself limitations for when you should or should not check for updates, on a quest to reduce the ceaseless flow of notifications. Opt in. Silence the useless.