As you use the site more you will likely have a number of subscriptions to different topics and will receive notifications via email when something new is added.
To view your subscriptions, you can click My Subscriptions on the left side menu (desktop) or the mobile menu.
You will be taken to your subscriptions page with a list of the discussion topics you are subscribed to.
If you are no longer interested in following a discussion, you can click on the link to go to the topic and then click Unsubscribe on that page. You will be unsubscribed from the topic and no longer receive email notifications for new updates. You can always subscribe again in the future if you want to receive updates again.