if (    (maxQuota == -1) || (quota == 0 && maxQuota != 0) || (quota > maxQuota)
if (maxQuota == 0) return true;  if (    (maxQuota == -1) || (quota == 0) || (quota > maxQuota)
    public boolean canModifyMailQuota(AuthToken at, Account targetAccount, long quota) throws ServiceException {        if (!canAccessAccount(at,  targetAccount))            return false;        Account adminAccount = Provisioning.getInstance().get(Provisioning.AccountBy.id,  at.getAccountId());        if (adminAccount == null) return false;        // 0 is unlimited        long maxQuota = adminAccount.getLongAttr(Provisioning.A_zimbraDomainAdminMaxMailQuota, -1);        if (    (maxQuota == -1) ||              // they don't permsission to change any quotas                (quota == 0 && maxQuota != 0) || // they don't have permission to assign unlimited quota                (quota > maxQuota)               // the quota they are tying to assign is too big                ) {            ZimbraLog.account.warn(String.format("invalid attempt to change quota: admin(%s) account(%s) quota(%d) max(%d)",                    adminAccount.getName(), targetAccount.getName(), quota, maxQuota));            return false;        } else {            return true;            }    }