RBL cache {Scanned by HJMS}

[Ugo Bellavance]

On Fri, 12 Sep 2003 16:17:52 -0500, Furnish, Trever G
<TGFurnish at HERFF-JONES.COM> wrote:

>If you wanted to do that, all you'd need to do is set up a caching-only dns
>server on your local system.  If your system is redhat, I think they include
>a package with the bind config meant specificly for that purpose.  I would
>think most people already have another local server doing dns lookups for
>them anyway, which is in effect a cache.  For example, my mailscanner uses
>another local server as its dns server - that server is on the same ethernet
>segment so there's very little difference compared to running my own cache
>on the mailscanner.  The DNS server is caching all the lookups - because
>that's just what DNS servers do.

--

I don't want to make a caching DNS. I know how to do that already.  What I
mean is, for example:

1-You get a message from domain.example.com.  Mailscanner checks with the
RBL.  The RBL finds it is on a spamlist.  Mailscanner identifies the message
as spam, puts the domain at example.com in a local cache, sets a ttl of, say, 4
hours.

2-Five minutes later, you get another message from domain at example.com.  In
the current setup, to my knoledge, the RBL must be contacted again.  In my
suggestion, MailScanner looks in its local cache to see if
domain.example.com is on the spam list.  It is on the spam list, so it won't
have to contact the RBL again for this address.

I think this suggestion would decrease the load on the RBL servers and on
the network, and it would allow faster processing, since it is faster to do
a local query than a network query.