Re: [exim] Preventing TXT lookups after successful acl modif…

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Author: Mar Matthias Darin
Date:  
To: exim users
Subject: Re: [exim] Preventing TXT lookups after successful acl modifier dnslists processing
Hello,

Graeme Fowler writes:

> Getting back to the OP's question, and your answer: Dynastop isn't doing
> TXT lookups, because it's doing a different thing entirely. It might
> reduce the number of TXT lookups for a given query, but that's because
> it isn't doing DNS lookups at all.


Correct, there are no TXT lookups.

DynaStop does a single realtime A ptr lookup. The result is stored in a
memory cache until expired. Depending upon how active an IP address is, it
may easily have several hundred hits from the cache as opposed to DNS
lookups.. On a clustered mail server with multi DynaStop clients, one
single lookup thoughout the entire cluster can be translated into a
significant savings in resources and bandwith shared across the entire
cluster. On a single non-clustered system, there will be a still savings as
DynaStop's cache will most likely outlive Exim's cache, depending on how
active the IP address is.

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DynaStop: Stopping spam one dynamic IP address at a time.
http://tanaya.net/DynaStop/