Email issues when registering new users

Currently, There are two issues that arise when a user is registering for the first time:
1. When a user registers, and enters an email address and number that already exists the system does not reject entry and allows users to share emails.
2. When a user sets up their account for the first time, no email neither the “Registration activate email” nor the “Registration success email”. Furthermore, NO email notifications work. This is probably due to the fact the email is populating only in the:
[WP >>> Users >>> Account Mngr >>> Email] section, when list should populate in both the “Account Mngr” section, and also in the “Contact Info” section, of the edit screen of the user profile.

Emails not saving upon registration per user accounts. They have to be added manually before user can get any email notifications in the User section of the WordPress Backend.
• used to work properly when users had to confirm email with a verification email click
• doesn’t work after allowing users auto registration