I'm sorry to hear about this. I just created a test stream for a social group, enabled email for everyone, and then created a document. A moment later, I can confirm I did receive an email with the same contents I had posted at my registered user's email address. If the issue persists, could you please try rebuilding the stream to see if that helps? This is found in the Jive Admin Console under System > Settings > News.
I had this problem previously, as it was a known bug following the inclusion of news streams. But I thought that bug was fixed in this latest update--I've been meaning to test it so I'll let you know what I find.
FYI, the workaround for us was that turning email on for new streams that were for a select audience did work. So I created one of those streams and then added everyone based on a profile field, called division. We only have three divisions in the company, and any new employees are automatically in one of the three. So it wasn't onerous to get everyone subscribed. That may not work for you, if there isn't a profile field you can use that collects up people easily. Hope that makes sense - let me know if I can clarify.
Thanks to you both for this useful information! I have rebuilt the stream and I'm currently waiting for some relevant information to post in this stream to see if it's working. Jessica, thanks for your alternative solution, I indeed thought about it, but the less large profile field we have is divided in 25 - and after 15 or so, Jive starts to get puzzled and doesn't not want to build the stream.
I'll keep you posted as soon as I try to post something!