The list can only be seen by the group managers. As the group creator, I'm currently the only one; but if some of the active old members of enjoysudoku wants to join, he'll be welcome. Just PM me.
To post there,
- either answer an existing "conversation" (currently only one: "Purpose of this group");
- or click the "+ Start new conversation" button (on Safari, it appears on the upper left side).
First posts of a new member are "moderated" in order to avoid spam. Honestly, I don't know how many posts "first posts" means.
I just see I can modify this member by member: so, I've already done it for people I could identify: no moderation for your first posts.