Notifications re. Posts. There’s 2 ways to control this.
Control notification by Category. Each Category and subCategory has a button upper right that gives you access to the notification settings for that category.
Your notification settings in your Profile. To get to your profile, click on your Avatar upper right and then click on the little gear symbol. Once at your profile, go to your Mail settings. Note that there is some cool fine-tuning of your notification settings here. The default settings are pretty good, so I’d encourage folks to give them a try before changing them.
Email settings are also in the profile. See above pic.