I've been trying to fix this of find out why the behavior

I've been trying to fix this or find out why the behavior is as it is.

My site is Multi-site, buddypress, bbpress theme is Buddy Press Busineess

1. User signs up to site and email confirmations and activation works.

2. Same user signs up for site after signing up and email confirmation works as it should and site is created.

3. Same user upgrades with Pro-sites using Paypal sandbox. Site is upgraded as it should be, users account charged in Paypal Sandbox, My admin account is credited in paypal sandbox.

No email confirmations to user or me(admin) for site upgrade and Paypal. Known at all.

I did this test a month ago and I thought I got confirmation emails. I've added MailChimp plugin and it has been activated. I deactivated it and had same behavior as I did before deactivation. I even deactivated and reactivated Pro Sites, same behavior.

OK, I'm stumped but I know some one knows what's going on. Please help!