If you want to stay up to date with certain forums and topics, you can easily subscribe to it and receive email notifications.
Here are examples of how to subscribe to an entire forum or an individual topic:
You can always visit your user profile to manage your subscriptions.
You can also bookmark topics, which gives you a way to go back and find important topics, but not receive too many notifications about them.
Lastly, when you're posting a new topic, you can subscribe to it right away by clicking one box.