wp_network_admin_email_change_notification

	$content = apply_filters( 'new_network_admin_email_content', $email_text, $new_admin_email );

	$current_user = wp_get_current_user();
	$content      = str_replace( '###USERNAME###', $current_user->user_login, $content );
	$content      = str_replace( '###ADMIN_URL###', esc_url( network_admin_url( 'settings.php?network_admin_hash=' . $hash ) ), $content );
	$content      = str_replace( '###EMAIL###', $value, $content );
	$content      = str_replace( '###SITENAME###', wp_specialchars_decode( get_site_option( 'site_name' ), ENT_QUOTES ), $content );
	$content      = str_replace( '###SITEURL###', network_home_url(), $content );

	wp_mail(
		$value,
		sprintf(
			/* translators: Email change notification email subject. %s: Network title. */
			__( '[%s] Network Admin Email Change Request' ),
			wp_specialchars_decode( get_site_option( 'site_name' ), ENT_QUOTES )
		),
		$content
	);

	if ( $switched_locale ) {
		restore_previous_locale();
	}
}

/**
 * Send an email to the old network admin email address when the network admin email address changes.
 *
 * @since 4.9.0
 *
 * @param string $option_name The relevant database option name.
 * @param string $new_email   The new network admin email address.
 * @param string $old_email   The old network admin email address.
 * @param int    $network_id  ID of the network.
 */
function wp_network_admin_email_change_notification( $option_name, $new_email, $old_email, $network_id ) {
	$send = true;

	// Don't send the notification to the default 'admin_email' value.
	if ( 'you@example.com' === $old_email ) {
		$send = false;
	}

	/**
	 * Filters whether to send the network admin email change notification email.
	 *
	 * @since 4.9.0
	 *
	 * @param bool   $send       Whether to send the email notification.
	 * @param string $old_email  The old network admin email address.
	 * @param string $new_email  The new network admin email address.
	 * @param int    $network_id ID of the network.
	 */
	$send = apply_filters( 'send_network_admin_email_change_email', $send, $old_email, $new_email, $network_id );

	if ( ! $send ) {
		return;
	}

	/* translators: Do not translate OLD_EMAIL, NEW_EMAIL, SITENAME, SITEURL: those are placeholders. */
	$email_change_text = __(
		'Hi,

This notice confirms that the network admin email address was changed on ###SITENAME###.

The new network admin email address is ###NEW_EMAIL###.

This email has been sent to ###OLD_EMAIL###

Regards,
All at ###SITENAME###
###SITEURL###'
	);

	$email_change_email = array(
		'to'      => $old_email,
		/* translators: Network admin email change notification email subject. %s: Network title. */
		'subject' => __( '[%s] Network Admin Email Changed' ),
		'message' => $email_change_text,
		'headers' => '',
	);
	// Get network name.
	$network_name = wp_specialchars_decode( get_site_option( 'site_name' ), ENT_QUOTES );

	/**
	 * Filters the contents of the email notification sent when the network admin email address is changed.
	 *
	 * @since 4.9.0
	 *