I want to create a user account for contacting developers using their own email addresses, not a new Gmail user in my account. Google Cloud Platform seems to let me create the users, but they never receive an email and hence can't complete the account creation.

As it happens, they are Google Docs users with their own Google accounts, but naturally they'd rather not have yet another email address. Is this even possible or does Google tie Google Cloud Platform into Google Docs? It seems a major limitation of Google Cloud Platform if they do.