[SC-Help] Re: Spamcop treats MX differently depending on where it appears in chain

[Blammo]

On 30 Mar 2005 You have no need to know entered spamcop.help and left
news:pan.2005.03.30.22.25.33.270552 at fl.net.invalid: 

> If the MX is the first receiver it gets marked as the spam source
> rather than the original source. (Before someone asks, the ISP has two
> names and all MXs for one are MXs for the other. I have munged one as
> ISP.MX and the other as isp-other-name.mx)
> 

Your first mistake is thinking that MX has anything to do with outgoing 
mail.
The sending server needs to send out the actual hostname, it can't use a 
name who's PTR resolves to a different hostname. If it does, Spamcop has to 
try to make a bunch of guesses to see if any match turns up. 
I have an ISP that uses 2 or 3 alternating relays and Spamcop has never got 
it wrong.
In your first example, why doesn't isp-other-name.mx match 4dmail.co.uk?

Even the spammers are figuring this out.
-- 
| Ric