From the Microsoft Tech Community:

SharePoint email notifications help you stay up-to-date with news, comments, and activities. We’ve recently announced notifications for comments, replies and likes on modern pages and news posts.

 

We know you want to control what lands in your inbox. Currently, you can unsubscribe from a category of notifications by clicking the Unsubscribe link in a notification email.

 

Email notifications settings panel

 

The email notifications settings panel, rolling out in late June 2019, enables you to manage all your email notifications from a single place. You can select the categories of email notifications you want to receive.

 

 

To access the email notifications settings panel, click the Manage your preferences link in a notification email.

 

Alternately, click SharePoint in the Office launcher (also known as the “waffle menu�). From the SharePoint start page, click the settings cog, then click Email notifications

 

As we add new categories of notifications, we will add them to the settings panel.

 

 

The above is kindly provided by the Microsoft Tech Community!