I'm using REST to create new users to our community, but the welcome email does not get generated when I do so through REST, only when we add users directly through the Membership administration. The only difference between the two is that when I do so through REST, I'm also populating various profile fields. Otherwise, the user gets created just fine either way, it's just that the welcome email does not get generated. Any ideas what would short-circuit that when created via REST?