RE: blowback, was A new SMTP "3821" [Re: FTC stuff...........]

On Sun, 9 Jan 2005 [email protected] wrote:

> 
> Agreed, but near sighted.  If the sending MTA had done some sort of validation to ensure the message
> was not forged when it accepted it, then we wouldn't have a blowback problem.  You cannot blame
> subsequent MTA's in the path for detecting and rejecting bad email when its something the first hop
> MTA could (and should) have done in the first place!

And just what sort of validation would that be?

You are talking about a normal closed relay. It cannot use SPF to validate 
its own users.

> His point I think is that if the virus is trying to send directly to the MTA it would get rejected
> with no bounce back (because the virus wouldn't process a bounce).
> 
> If an MTA.1 accepted a virus message, and tried relaying it to MTA.2, when MTA.2 rejects it as
> forged, and MTA.1 processes a bounce, well, NO SYMPATHY FOR MTA.1, it should have taken steps to
> prevent the virus/forgery etc from being accepted by itself in the FIRST PLACE.

Your lack of sympathy for MTA.1 is unfortunate, but unrealistic.  Even
taking steps to prevent viruses does not catch all virues.  Even using
SMTP AUTH on a closed relay does not prevent forgery.

		--Dean


-- 
Av8 Internet   Prepared to pay a premium for better service?
www.av8.net         faster, more reliable, better service
617 344 9000