Disable the administration email address verification (new in 5.3)

This new feature was added in 5.3 from core ticket #46349

Currently (in 5.3) we have [src] in wp-login.php:

 /**
  * Filters the interval for redirecting the user to the admin email confirmation screen.
  * If `0` (zero) is returned, the user will not be redirected.
  *
  * @since 5.3.0
  *
  * @param int Interval time (in seconds).
  */
  $admin_email_check_interval = (int) apply_filters( 'admin_email_check_interval', 6 * MONTH_IN_SECONDS );

  if ( $admin_email_check_interval > 0 ) {
     update_option( 'admin_email_lifespan', time() + $admin_email_check_interval );
  }
  wp_safe_redirect( $redirect_to );
  exit;

and also the logic [src]:

$admin_email_lifespan = (int) get_option( 'admin_email_lifespan' );

// If `0` (or anything "falsey" as it is cast to int) is returned, the user will not be redirected
// to the admin email confirmation screen.
/** This filter is documented in wp-login.php */
$admin_email_check_interval = (int) apply_filters( 'admin_email_check_interval', 6 * MONTH_IN_SECONDS );
if ( $admin_email_check_interval > 0 && time() > $admin_email_lifespan ) {
    $redirect_to = add_query_arg( 'action', 'confirm_admin_email', wp_login_url( $redirect_to ) );
}

So we can disable the screen by filtering the admin email checking interval to zero with a (must-use) plugin like:

<?php /** Plugin Name: WPSE-353167: Disable Admin Email Checking Screen **/
add_filter( 'admin_email_check_interval', '__return_zero' );

Here __return_zero() is a core helper function that returns the zero integer. We could also return values that are not greater than zero when converted to an integer (e.g. false, null, '0', … ).

There’s also an open ticket #48153 to make this more flexible regarding the capability filtering.

Here are the published the dev notes.