[OpenIndiana-discuss] Qmail-to-go on openindiana?

Christopher Chan christopher.chan at bradbury.edu.hk
Fri Apr 27 02:53:05 UTC 2012


On Thursday, April 26, 2012 08:30 PM, Gary Gendel wrote:
> On 4/26/12 5:01 AM, Christopher Chan wrote:
>> On 26/04/12 12:17 AM, Gary Gendel wrote:
>>
>>> That isn't what spamdyke is trying to accomplish here. This checks to
>>> see if the sender is trying to spoof the MTA. What spamdyke is 
>>> trying to
>>> do is to blacklist emails based upon the ip address embedded in the
>>> sending domain name. For example:
>>>
>>> If I get mail from 208.1.48.3 and it's reverse domain lookup 
>>> resolves to
>>> customer.208.001_48.3.sample.com and sample.com is on my list it is
>>> blocked.
>>>
>>
>> Again, it's available with the following configuration parameter:
>>
>>    check_reverse_client_hostname_access type:table
>>
>> Table should have key "sample.com" and RHS = REJECT, blah
>>
>> Table details:
>>
>> http://www.postfix.org/access.5.html
>>
> Chris, I'm still unclear on how to do this.  How could you write a 
> regular express to check to see if the connecting ip address is buried 
> in the reverse dns lookup.
>
> In my example, spamdyke would reject customer.208.001_48.3.sample.com, 
> but customer.108.001_48.3.sample.com would not be rejected because it 
> doesn't match the ip address of the sending MTA.  This prevents 
> rejecting reverse dns names with strings of arbitrary numbers in them.

Gary,

I am sorry, but things are a bit unclear here. Is it "don't block 
misconfigured clients but do block clients with proper rdns in this domain"?

What do you mean by "customer.108.001_48.3.sample.com would not be 
rejected because it doesn't match the ip address of the sending MTA"? 
That customer.108.001_48.3.sample.com A would not map back to the ip of 
server whose PTR record points to customer.108.001_48.3.sample.com?

Christopher



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