If you are using Google Apps for your domain (at least the Business version -- maybe the free one too), you can setup a private Google group and CC it to store

If you are using Google Apps for your domain (at least the Business version -- maybe the free one too), you can setup a private Google group and CC it to store such information and make it accessible and searchable to others using your Google App domain. Of course, you can also use Google Groups for a private mailing list, but here you can store a thread (which, like gmail, is nicely collapsed) without having to synchronize everyone joining your group. Handy for document support requests via email.