Now we are trying to evaluate Zoho Campaigns. 

Zoho Campaigns instance was created using an admin account crm@alleader.com.br (which is a single alone google account...  our domain isn't under gapps).

Now when adding others users of alleader.com.br domain, the users are added sucessfuly, and they can sign in into Zoho Campaigns. But when a user tries to create a new campaigns, he receives an error about no mail address available to use. In Settings/Sender address settings, everything looks checked and verified.

This error is related to google/gapps account Zoho Campaigns instance activation?