MessageFolder::getDirIdForMessages

static function getDirIdForMessages($mailboxId, $messagesIds)
{
	$dirWithMessagesId = MailboxDirectoryTable::getList([
		'runtime' => array(
			new MainORMFieldsRelationsReference(
				'UID',
				'BitrixMailMailMessageUidTable',
				[
					'=this.DIR_MD5' => 'ref.DIR_MD5',
					'=this.MAILBOX_ID' => 'ref.MAILBOX_ID',
				],
				[
					'join_type' => 'INNER',
				]
			),
		),
		'select' => [
			'ID',
		],
		'filter' => [
			'@UID.ID' => $messagesIds,
			'=MAILBOX_ID' => $mailboxId,
		],
		'limit' => 1,
	])->fetchAll();

	if(isset($dirWithMessagesId[0]['ID']))
	{
		return $dirWithMessagesId[0]['ID'];
	}
	return false;
}