WordPress at a glance
filter is not described

auto_core_update_send_email filter-hook . WP 3.7.0

Filters whether to send an email following an automatic background core update.

Usage

add_filter( 'auto_core_update_send_email', 'filter_function_name_4530', 10, 4 );
function filter_function_name_4530( $send, $type, $core_update, $result ){
	// filter...

	return $send;
}
$send(true/false)
Whether to send the email.
Default: true
$type(string)
The type of email to send. Can be one of 'success', 'fail', 'critical'.
$core_update(object)
The update offer that was attempted.
$result(mixed)
The result for the core update. Can be WP_Error.

Where the hook is called

WP_Automatic_Updater::send_email()
auto_core_update_send_email
wp-admin/includes/class-wp-automatic-updater.php 600
if ( 'manual' !== $type && ! apply_filters( 'auto_core_update_send_email', true, $type, $core_update, $result ) )

Where the hook is used (in WP core)

Does not used.