[Mimedefang] received headers ofuscation

[Kevin A. McGrail]

> Why are you trying to mess with Received: lines?  That's a VERY bad idea.
> RFC 2821 discourages this kind of thing most strongly:
>
> 3.8.2 Received Lines in Gatewaying
>
>   When forwarding a message into or out of the Internet environment, a
>   gateway MUST prepend a Received: line, but it MUST NOT alter in any
>   way a Received: line that is already in the header.
>

Unrelated side-note, I've been considering modifying the received headers to 
remove IP relays because of Barracuda, for example, is doing deep header 
parsing on received headers.

We've had a number of issues now where I've seen internal and bug reports 
for SA that turned out to be DHCP addresses from BIG providers like Verizon 
that are rotated to the next customer. Then the customer uses those 
addresses to properly authenticate and relay only to be marked/blocked as a 
spammer!

Regards,
KAM