If you want to know when a new version of CC Mode is available, join the announcement only mailing list.

You can also browse or join the general mailing list for CC Mode, which gets all the bug reports, feature requests, and everything else concerning CC Mode that is sent to bug-cc-mode@gnu.org. It's a mailing list mostly for archiving purposes; although the list is moderated (to deal with spam) you don't need to be a member to post to it or to get the replies to your mails.

Note that it regrettably happens that I (Alan) don't always answer the mails very quickly. Bugs which are easy to fix, especially if reported concisely, are usually tended to fairly swiftly. Feature requests and more difficult bugs might not get answered for a while. That's especially true for things I'm working on right now since I tend to postpone an answer until I have something to show (yes, that's a bit silly). Still, rest assured that such unanswered requests remain tagged in my mailbox and will be answered eventually.