Re: [exim] Re: bounce messages and their potential misuse

On 30/03/06, Adam Funk <adam00f@???> wrote:
> On 2006-03-30, Peter Bowyer <peter@???> wrote:
>
> > You're right, it wouldn't use callouts. But instead, it has a closed
> > community of known senders for whom it relays, and it can safely
> > assume that none of them is forging its sender address - so if it gets
> > a rejection on a relayed message, it can return it to the sender
> > knowing that the sender address is genuine.
>
> I think you're saying that MTA(n-1) should be confident that it is
> handling mail with good senders' addresses, although it can't know
> about the recipients' addresses, whereas MTA(n) can distinguish good
> and bad recipients' addresses and has to assume that MTA(n-1) has
> checked the senders' addresses.

Exactly.

> Now when we say "senders' addresses", which headers are we talking
> about? For example, I send mails from my home computer with various
> from-addresses (mainly one for work and one for personal stuff), none
> of which is associated with my ISP.

If the MTA you're relaying through doesn't care about the sender (the
MAIL FROM address, nothing to do with headers), then it's broken.

Peter

--
Peter Bowyer
Email: peter@???