Imap::getMinimumSyncDate

public function getMinimumSyncDate()
{
	$minimumDate = false;

	if(!empty($this->mailbox['OPTIONS']['sync_from']))
	{
		$minimumDate = $this->mailbox['OPTIONS']['sync_from'];
	}

	$syncOldLimit = MailHelperLicenseManager::getSyncOldLimit();

	if($syncOldLimit > 0)
	{
		$syncOldLimit = strtotime(sprintf('-%u days', $syncOldLimit));

		/*
			Checking in case of changes in tariff limits
		*/
		if($minimumDate === false || $minimumDate < $syncOldLimit)
		{
			$minimumDate = $syncOldLimit;
		}
	}
	return $minimumDate;
}