If someone requests to join the Clojure Dev Google group but they are not on the contributor's list, they should not be approved for joining the group until they have signed a CA. One way to do this that keeps the list of pending join requests small is to immediately decide whether to approve or reject the join request when you examine it. Based on the join request, if you can confirm that they are currently on the list of contributors, approve immediately. If you cannot confirm that (even if that is simply because the join request has an email address but no recognizable name), reject immediately and send an email explaining why they were rejected, and what they can do about it (sample email is given below under heading "Form reply ...").
Note that Confluence groups cannot be renamed (http://jira.atlassian.com/browse/CONF-13571). Sorry the names aren't pefect.
These are places I went when configuring Confluence:
Subject: Your request to join the Clojure Dev Google group is being rejected
It is currently the policy of the Clojure core development team to only accept requests to join the Clojure Dev Google group after they have received a signed CA (Contributor's Agreement) for Clojure. If you were interested in doing that, but have not already, details are available here: http://clojure.org/contributing
Note that there is no need to submit any contributions to Clojure before submitting a signed CA. Many people who have signed a CA have not yet contributed any patches to Clojure even after signing a CA.
If you have already submitted a CA, but it hasn't been processed yet, please wait until your name appears on the list of contributors on that page, and then re-apply to join the Clojure Dev Google group. Your request will be approved then.
The Clojure Google group (without "Dev" in the name) is open to anyone to join and discuss Clojure programming, including how it is implemented and any desired changes to the language. Most or all of the Clojure contributors belong to it as well.
Although it isn't the same as getting the Clojure Dev group messages in your inbox, you can browse messages on the web at http://groups.google.com/group/clojure-dev or get an Atom or RSS feed of them at http://groups.google.com/group/clojure-dev/feeds.