[PLUG] Mail Administration Question

[Louis Kowolowski]

I’ve found that too many mail domains don’t have proper DNS setup and blocking based on this will generate problems for people. You can however configure SpamAssassin to increase the score based on DNS unresolvability. I would suggest this. It also leaves the ultimate decision up to the recipient on whether they wish to filter the mail or not, which I believe is the correct thing to do.

Note that these comments are based on the perspective of running multiple domains and many users all on the same systems. If its just your personal mail, you can take certain liberties that others may not be able to.


> On Apr 6, 2015, at 8:10 AM, Rich Shepard <rshepard at appl-ecosys.com <mailto:rshepard at appl-ecosys.com>> wrote:
> 
>   Much spam passing current postfix UCE filters and landing in the INBOX are
> from IP addresses that do not resolve to a domain name. The headers include
> a 'Received: from <some_domain_name> (unknown [nnn.ooo.ppp.qqq])'.
> 
>   Is the unknown IP address a reliable indicator of spam? A Web search did
> not answer this question. One hit, to an Apple mail forum, suggested that it
> can be the result of some (many?) Mac admins not correctly configuring their
> DNS servers.
> 
>   Might adding a rule to reject unknown IP addresses produce unintended
> consequences of rejecting legitimate non-maillist messages?
> 
> Rich
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--
Louis Kowolowski                                louisk at cryptomonkeys.org <mailto:louisk at cryptomonkeys.org>
Cryptomonkeys:                                   http://www.cryptomonkeys.com/ <http://www.cryptomonkeys.com/>

Making life more interesting for people since 1977

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