When a new user signs up to your WordPress site, an email notification is sent to the “admin address” specified on Settings > General > Email Address:

This email address is used for ALL notifications, and unfortunately, you can’t set a different email just for the “New User Registration”.

Luckily, there is a way to fine-tune the “new user registration” notifications and send them to a different email address other than the “admin email address”.

Open your theme’s functions.php (Appearance > Theme Editor > Theme Functions):

// functions.php

/** "New user" email to [email protected] instead of admin. */
add_filter( 'wp_new_user_notification_email_admin', 'my_wp_new_user_notification_email_admin', 10, 3 );
function my_wp_new_user_notification_email_admin( $notification, $user, $blogname ) {
    $notification['to'] = '[email protected]';
    return $notification;
}

That’s it!

In the example, we changed the email address to “[email protected]“, by using the wp_new_user_notification_email_admin filter.

There are 4 variables you can use: to, subject, message, headers.

Let’s use the headers to send the notification to “[email protected]” as a CC and keep the admin email as the recipient:

/** "New user" email to [email protected] instead of admin. */
add_filter( 'wp_new_user_notification_email_admin', 'my_wp_new_user_notification_email_admin', 10, 3 );
function my_wp_new_user_notification_email_admin( $notification, $user, $blogname ) {
    $notification['headers'] = "From: My Blog <[email protected]> \n\r cc: John Snow <[email protected]>"
    return $notification;
}

WordPress 4.8 and before

This solution only works for WordPress 4.9+. For older versions, the filter wp_new_user_notification_email_admin doesn’t exist, but you can redeclare the WP core function wp_new_user_notification() as it is a pluggable function.

---

WP_REST_User plugin

If you use the “WP_REST_User” plugin to create users via Ajax/REST, be aware that it doesn’t trigger a wp_new_user_notification() by default. So, you will need to add this:

/* Called on sign up via WP_REST_User plugin. */
add_action('wp_rest_user_user_register', 'my_wp_rest_user_register');
function my_wp_rest_user_register( $user ) {
    /** Send "New user registration" email to admin. */
    wp_send_new_user_notifications( $user->ID, 'admin' );
}

Change admin to both if you want to send a notification to the user too.

The user notification is different than the admin. You can fine-tune the user notification using the filter wp_new_user_notification_email (same 3 arguments on function and same 4 customizable fields).