Helper::updateMailboxUnseenCounter

static function updateMailboxUnseenCounter($mailboxId)
{
	$count = InternalsMailCounterTable::getList([
		'filter' => [
			'ENTITY_TYPE' => 'DIR',
			'MAILBOX_ID' => $mailboxId,
		],
		'runtime' => [
			new BitrixMainEntityExpressionField('COUNT', 'SUM(%s)', 'VALUE'),
		],
		'select' => [
			'COUNT'
		]
	])->fetchAll();

	if(!is_null($count[0]["COUNT"]))
	{
		static::setMailboxUnseenCounter($mailboxId,(int)$count[0]["COUNT"]);
	}
}