Notifications for Plesk Administrator are duplicated to another email address

Applicable to:

There are additional administrator accounts.
Notifications are sent to another email address, different than specified for administrator in Tools & Settings > Notifications or Plesk > Profile & Preferences for example john.doe@example.com.
Email address assinged to the additional administrator account in Plesk database:

# plesk db "select login,aemail from admin_aliases where aemail='john.doe@example.com'"
+--------------+-------------------+
| login | aemail |
+--------------+-------------------+
| example | john.doe@example.com |
+--------------+-------------------+

Email for additional administrator accounts is incorrect.

Solution 1:

Log in to Plesk under the primary administrator account.
Change the email for proper one: Tools & Settings > Additional Administrator Accounts > example > Email.

Solution 2:

Log in to Plesk under the primary administrator account.
Delete additional administrator account: Tools & Settings > Additional Administrator Accounts > example > Remove.

Solution 3:

Log in to Plesk under the primary administrator account.
Suspend additional administrator account: Tools & Settings > Additional Administrator Accounts > example > click More > Suspend.