nanog mailing list archives

Re: Has postini been taken over?


From: Ray Wong <rayw () rayw net>
Date: Thu, 19 Aug 2004 22:17:04 -0700


On Fri, Aug 20, 2004 at 07:53:05AM +0300, Hank Nussbacher wrote:

At 09:14 AM 19-08-04 -0700, Jay Hennigan wrote:

Have you or a mail administrator for your domain signed up with Postini
for spam filtering?  If so, all mail for the domain will flow through

How exactly does "all mail for the domain will flow through
Postini's servers"?  I ask since the IP sending to some postini IP like 
exprod5mx30.postini.com is blocked for outgoing port 25+80.  That means 
that the data is flowing to postini in 1 of the following ways:

a) auto-GRE tunnels
b) email packaged in some way
c) email is being sent via some dialup/DSL connection to postini


You're making this entirely too complicated.  Just because mail can't
enter postini's network via the address it comes from, doesn't mean it
can't enter it on a different IP.  Postini's a mail filtering company,
I'd be willing to bet they have a lot of IPs that allow inbound mail. :)


I am just trying to understand how postini is bypassing my anti-spam ACLs.

Again, you haven't answered his question.... Did your ISP or some other
email provider possibly sign up for Postini?  How many different domain
addresses forward into your account?  If you accept mail from any other
server for any other domain, that domain could be a postini customer.
Postini does not originate or forward spam, they filter mail destined for
their customer domains.  Some spam gets through their filters, because
spammers are smart and adaptively evil.  It's really quite simple.  


-- 

Ray Wong
rayw () rayw net


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