RES: RES: source mail server IP differs from MX IP

  • From: "Tiago de Aviz" <Tiago@xxxxxxxxxxxxxxx>
  • To: "[ExchangeList]" <exchangelist@xxxxxxxxxxxxx>
  • Date: Tue, 29 Mar 2005 13:49:03 -0300

I don't believe so. You would pass most checks like reverse DNS and MX check. 
Many of my customers deliver mail thru different servers that receive with no 
issues at all.

Tiago de Aviz

SoftSell - Curitiba

(41) 340-2363

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-----Mensagem original-----
De: Dan Klobnak [mailto:dan.klobnak@xxxxxxxxxxxxxxxxxxxxxxx] 
Enviada em: terça-feira, 29 de março de 2005 10:57
Para: [ExchangeList]
Assunto: [exchangelist] RES: source mail server IP differs from MX IP

Tiago, I am not 100% sure that I will have that option, but I appreciate
the suggestion. 

Going back to my original scenario: is it a potential source of issue?
Thanks! D

Subject: RES: source mail server IP differs from MX IP: potential
blacklist ramifications?
From: "Tiago de Aviz" <Tiago@xxxxxxxxxxxxxxx>
Date: Mon, 28 Mar 2005 17:20:53 -0300
X-Message-Number: 12

Why not relay mail through the UNIX box too?

Tiago de Aviz

SoftSell - Curitiba

Subject: source mail server IP differs from MX IP: potential blacklist
From: "Dan Klobnak" <dan.klobnak@xxxxxxxxxxxxxxxxxxxxxxx>
Date: Mon, 28 Mar 2005 06:37:17 -0600
X-Message-Number: 4

Hi there,=20

My eyes have been swimming from all the reading I did this weekend, and
this last issue was when I was a couple short of a six-pack...both =
literally and figuratively.=20

We are dealing with SPAM (who isn't). But have no real solution in place
right now. One particularly attractive option: not making it my problem.

My company recently merged with another company, which has an IT staff =
of 12 to my one with apprentice. They have Saphos Puremessage for Unix =
in place, and offered to help.=20

The idea seems simple enough.
I modify my MX to their perimeter X.X.X.X server.
They filter and forward to our server based on a table entry similar to

However, all my sent messages will originate from my Y.Y.Y.Y ip (I'd =
rather not have it go back through their system)

So, does this pose a potential issue regarding blacklists. I *believe* =
one method of determining SPAM sources is a comparison of source IP to =
public record (MX)? Or am I really way off on the idea of Reverse DNS?

Thanks for the insights! Dan

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