MailboxDirectory::getMinSyncTime

static function getMinSyncTime($mailboxId)
{
	$res = MailboxDirectoryTable::getList([
		'filter'  => [
			'=MAILBOX_ID' => $mailboxId,
			'=IS_SYNC'    => MailboxDirectoryTable::ACTIVE,
		],
		'select'  => ['MIN_SYNC_TIME'],
		'runtime' => [
			new ExpressionField('MIN_SYNC_TIME', 'MIN(COALESCE(%s, 0))', 'SYNC_TIME'),
		]
	])->fetch();

	return (int)$res['MIN_SYNC_TIME'];
}