Maps Engine isn’t listed in my Google Apps Control Panel
If you’re an administrator, you might notice that the Control Panel that you use to manage users and groups has no Maps Engine entry under Organization & users > Services. This is by design and won’t cause problems.
You might also be puzzled if your domain doesn’t use Google Apps for Business (or Gmail), and you notice that Gmail appears to be enabled. The reason is that Maps Engine is using Google Apps Control Panel and a subset of the Gmail infrastructure to provision and manage users. In this unique case, although the user interface shows Gmail as enabled, mail delivery is not enabled, as you have no mail quota.