The following is closely related to Notification for questions marked as favourites?. When looking at "Prefs" under my profile, there is an option to "Allow email notifications when I subscribe to questions or tags". Yet, I cannot find any way to subscribe to a question. Am I missing something? If not, perhaps the text on the site should be revised ... alternatively (and that would be my favorite choice), it would be great if we could subscribe to questions and get inbox notifications of new answers, edits or comments to that question just like we do for the questions we ask.
This might not be exactly what you are looking but there is a feature for getting emails with inbox notifications from Stack Exchange sites.
In the page for posting questions, https://tex.stackexchange.com/questions/ask, there is a link to the dialogue for inbox notifications. The link is at the mouse pointer in the following screenshot:
You can also reach this dialogue by pressing the Stack Exchange menu in the top left corner of every Stack Exchange site and then press "email settings".