Maybe I was confusing things. Nevertheless, I do not get an email about site-wide notices published. When I login I can see the notification on the bp nav bar, but no email.
Hmm, funnily enough my impression/experience is different. BP Group Email Subscription may be working ok sending emails, but if I do not request emails from this plugin, I won’t receive any notification emails for my forum topics from core BuddyPress. I wonder if the Group Email Subscription does interfere with the correct functioning of the core BP notification system…or it is actually a bug in BP.