This patch does not appear to be working for me.
Initially it'll show the excluded group as saved (see image below). However, upon page refresh, the value is no longer selected.
I checked the core_sys_conf_settings table and the abg_group_exclude parameter is not being set. It just shows as NULL no matter what I select/save.
I found this out as I have a group on my forum for accounts that have invalid email addresses (bounce backs, rejections, etc) and I saw a few emails bouncing back from members in that group. So it's not being saved properly in the DB for some reason. How is the data supposed to look/stored in that parameter (single digit, comma deliminator, other?). I can manually update it for now for the group.
Thanks in advance!