There are a few preferences that you can configure in the following settings:
Email digest type: this determines how often a user will receive any posts from forums for which they are subscribed to. This will allow them to receive messages individually or on a daily.
There are 3 options:
No digest: this means the user will receive one email per forum post (this could cause a lot of frustration for your learner if the forum is very active and they may unsubscribe)
Complete: this means the user will receive 1 email per day containing the complete contents of each forum post
Subjects: they will receive 1 email per day containing just the subject of each forum post
You can change these settings in the site administration and search for User default preferences:
Forum auto-subscribe: this will specify if a user will receive copies of any posts that are added to forums in which they have previously posted. This can be manually overridden in the forum.
Forum tracking: by enabling tracking it will highlight posts that have not yet been read
When sending forum post notifications: when notified of a forum post you can choose whether this should mark the post as read for the purpose of forum tracking.