If you @mention the group itself, anyone who follows that group should get notified of the mention.
That Kirsten said is correct, so long as the members of that group have opted to follow and receive notifications for that group. If users have opted out, those users will not receive notification. There's no out of box way to force members of a group to receive emails by group @mention, as this may be undesirable for the other segment of users who don't want to subscribe to these. If the intention is to send an email rather than an @mention, then you do have the option to email the entire group list via as an owner/admin of the social group via Manage > Members > Send email to group.
What I've used in our internal Jive environment within the company is to create and manage my own "Labels" and this satisfies the requirement for me, but is probably not manageable for large lists. I'm not sure which version of Jive you're on, but for the latest version of Jive Cloud, here's the documentation covering this topic (and it should be similar for other newer versions of Jive as well):
Let me know if you have any other questions on this.
THanks for this. Exactly what I was looking for. We have just launched Jive internally and not everyone has got into the habit of logging in yet so as admin of the group I just wanted to share a particular post with everyone, so the email group from the admin menu was perfect.