[Asrg] where the message originated (was: DKIM role?) (SM)

[Daniel Feenberg]

On Mon, 19 Jan 2009, Paul Russell wrote:

> On 1/19/2009 10:38 AM, Ian Eiloart wrote:
>> 
>> I agree, but bounces have two huge advantages,
>> 
>> 1. You can bounce selectively. IE, you can accept a message for one 
>> recipient, while bouncing it for another, even after seeing the content. 
>> So, you can have different delivery policies for different people.
>
> I know that sendmail can be configured to accept for one recipient and reject
> for another recipient.  I assume there are other MTA products which also
> support this functionality.  If yours does not, perhaps you should consider
> using a different MTA.

If I may contribute...

Sendmail can selectively reject receipients while processing "RCPT TO:" 
commands, but not after the header and body are received. So anti-spam 
processing based on the sending IP address can be different for different 
users (and still use rejection rather than DSNs), but it isn't 
straightforward to selectively handle items based on content or headers 
without resorting to DSNs or spam folders.  That is one of the advantages 
DNSBLs have over content analysis. Or do you have a specific suggestion? 
As I understand it, this is a consequence of the SMTP protocol, and not 
something that sendmail can program around.

Dan Feenberg