Admin approval email

Hello, I have an opigno platform where the users should be registered in order to use it. Upon their application of their registration, an email is sent to admin in order for the new user to be approved. A few months ago the administrator was different and now that I changed the admin's email in the platform, at the "Hello admin" tab, the application are sent to the email of the previous user. Could you please suggest me a solution on that? Thank you