Re: [exim] require_verify = sender + RBLs - clarification on…

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Author: Andrew - Supernews
Date:  
To: exim users
Subject: Re: [exim] require_verify = sender + RBLs - clarification on the How-to
>>>>> "Alon" == Alon <js@???> writes:

Alon> RBLs (hey,. it's in the subject line!):


Since no-one else seems to have responded...

Alon> I can use RBLs like the following:

[snip]

Alon> but my concern is that at one point if I get lots of emails,
Alon> I'll be actually considered as a "hostile" checker and get
Alon> blacklisted for excessive checks.


Alon> Is that likely to happen?


No, providing you're staying within whatever terms and conditions
apply to the specific DNSBLs you're using, and provided you're not
deliberately breaking DNS caching.

DNS queries are (from the publishing server's point of view) a pretty
lightweight and efficient way to distribute the data. For a blacklist
that lists individual IPs, updates frequently and is large enough to
be useful, the break-even point for the blacklist publisher as to
whether DNS queries or rsync is most efficient is typically somewhere
between 1 million and 5 million queries per day.

Not all DNSBLs are available for free rsync of course (Spamhaus
certainly is not, haven't checked on the others you mentioned). For
the ones that are, maintaining your own mirror is usually unwise
unless you know _exactly_ what you're doing - you're more likely to
have problems caused by your own setup breaking. The reduced latency
for lookups isn't likely to be a significant benefit _unless_ you're
out in the weeds somewhere with a slow or congested pipe.

--
Andrew, Supernews
http://www.supernews.com