No Confirmation Emails Being Sent (Subdomains)

I have a Wordpress Multisite installation with the Membership Plugin activated. Everything on the site is working great but I have one major problem. I've looked all over for a solution, so hopefully someone here can help.

The problem is that subdomains don't send a confirmation email when a new user is added or if the admin email address has changed. This is not a problem at the network level.

I've allowed owners/administrators of subdomains to add new users to their subdomain even if they're not registered at the network level. Unfortunately, only a super admin can add users because a confirmation email is never sent.

Please help.

Thanks!