Please give as check-boxes to simply choose which user-groups we want to send email to. If I understood this correctly, I'm able to send emails to all groups or single user-group, when we talk about primary membership? Additionally, I can exclude groups, but there is no way to send email to users of groups 2,10 and 12 for example? Again, I'm talking about primary membership. Wouldn't be better to give us check-boxes instead of drop-down menu here?