On 4/5/2012 12:52 AM, Nataraj wrote: > On 04/04/2012 08:48 PM, Bob Hoffman wrote: >> No idea where else to ask this and get a real qualified answer but here. >> Not exactly pure centos question....but... >> >> I am adding blacklists to my postfix smtpd settings. >> I have the inkling that after the first lookup for a domain or ip that >> my dns caches the result and I no longer bother the RBL or RHSBL list >> owners anymore in that instance. >> >> Is that correct? I hate to waste their resources if it is not. >> >> thanks, >> bob >> >> >> _______________________________________________ >> CentOS mailing list >> CentOS at centos.org >> http://lists.centos.org/mailman/listinfo/centos > Not exactly. It is whatever TTL they return, though generally short for > two reasons, they and you probably want it so that they can quickly > remove entries from the blacklist once issues have been resolved. > > They want to know how often you query the blacklist, because they want > to charge a fee if you are a large site with high volume queries. I > guess they need to fund their service somehow. > > > Nataraj > > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos > > yea, I am already sending donations..well worth it. they 100,000 or more queries and then you can have access to the lists to download..though that ranges from 250 to 1000 a year, for each one....yikes. Still, well worth it if you have the cash and have a lot of users.