[Mimedefang] Black Listed

Daniel Taylor dtaylor at vocalabs.com
Wed Apr 7 07:53:24 EDT 2004


Andrea Venturoli wrote:
> ** Reply to note from WBrown at e1b.org Tue, 6 Apr 2004 15:10:33 -0400
> 
> 
> 
>>>>My ISP here (Bigpond) is about to implement blocking port 25 for all  
>>
>>their  
>>
>>>>dynamic IP customers. 
>>>
>>> 
>>>Good! That's ok with me, as soon as their smtp server, which I'm  
>>>then forced to use is not blacklisted! 
>>
>>   
>>This would not be acceptable to me at home on my cable modem.  I only use  
>>my cable modem ISP for transport only.  My mail accounts require  
>>authentication before I can relay off them.  If I relay through an  
>>Adelphia server, but have a StumpyDogs.org or RVClub.net address on the  
>>email, that could look like a forgery.
> 
> 
> There could be workarounds.
> Like for example allowing connection to outside servers on port 587, which should be authenticated.

SPF can help here. I have mx:mn.rr.com set for argle.org so that 
receiving mailservers know that argle.org e-mail can originate from
RoadRunner's servers legitimately. Port 587 should only be used for 
authenticated submissions to keep from being an open relay.

-- 
Daniel Taylor          VP Operations            Vocal Laboratories, Inc.
dtaylor at vocalabs.com   http://www.vocalabs.com/        (952)941-6580x203



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