Thanks for the code snippet. Our developer had to do this for a private unlisted group because the members of the group were angry that they were getting e-mails for every single forum post.
The feature may work for some scenarios like a small 10 person group like a working group, but after you get past a small group I am not seeing the advantage for this feature. I would love to see the option in the control panel when setting up a group or forum that we could pick if we want the members to be auto subscribed or not.
Thanks again for your help on the question guys.