Author: Tor Slettnes Date: To: Tony Finch CC: Exim User's Mailing List, Chris Edwards Subject: Re: [Exim] Final Peer Review Sought: "Spam Filtering for MXs" HOWTO
On Jul 13, 2004, at 03:01, Tony Finch wrote:
> On Mon, 12 Jul 2004, Tor Slettnes wrote:
>>
>> It is true that sender callouts are of limited use, since they only
>> verify the validity, not the authenticity of the sender address.
>
> If the sender signs their return path addresses then callouts verify
> both validity and authenticity. This is a powerful anti-forgery
> mechanism.
