Make email digests opt-in for new users?

I see that there is an option to disable email digests for all users, but I think it would be nice to be able to disable email digests for new users by default, so email digests become an opt-in feature. That way, only people who want email digests will get them from our forum. Thanks! : )

Check out the default email digest frequency site setting. Changing that will only affect new registrations.