Yes, each online AwesomeBox group is private.
Only the host and invited participants have access to the private online group. It is not discoverable online or cataloged by search engines.
After the deadline (which is determined by the host), AwesomeBox recipients will receive a link to access the group after they get their AwesomeBox in person. Here is an article about how and when that happens: Will you email recipient?
Other useful articles: