Customized Subscription

How do I edit the subcription setting on my forum so subcribers recieve a weekly digest of all post instead of an instant notification of any post and replies?

[GregChapman]

Such a setting is not directly available.

Users can choose a daily digest but not a weekly one.

However, it would be possible for you to create a sub-forum into which you post a collection of daily digests on a weekly basis. Your users would then need to subscribe to that sub-forum.

Note that it is always up to users to decide whether to make any subscription. An administrator cannot force a subscription on a user.