Sign up emails not being sent to member or admin

I am doing testing of sign ups and have run into a problem with the automatic emails not being sent.

The activation email is not being sent to the new member.
The notification of new sign up is not being sent to the admin.

I have disabled all plugins and there is no change.

I am able to create new sites myself through my dashboard and I do receive emails as the admin that a new site is created. I can send and receive emails just fine but the automatic emails on new sign ups are not being sent.

Can someone please tell me how to go about fixing this?