Following Tasks
If you follow a task, you will be notified about activities happening on the task e.g. when someone adds a comment or when someone attaches a file. The notifications will be through email as well as through the notification center. If you are an assignee or a project manager, then you are automatically notified and there is no need to explicitly follow the task.
Unfollowing
To unfollow a task, simply click on the Unfollow link on the task screen on in the footer of the email notification.
You can reply to the email notification to record your comment for that task!