[ietf-dkim] DKIM on envelope level

[Mark Delany]

On Oct 29, 2009, at 9:11 AM, Dave CROCKER wrote:

I'm guessing the incentive for all of this is to reduce bandwidth,  
otherwise why not just issue the 4XX/5XX after the DATA/. sequence  
rather than invent a new mechanism to issue the same response at the  
envelope end of the transaction?


> First blank line after DATA.
>

If the proposal is an attempt to reduce SMTP bandwidth, which is  
becoming a vanishingly small part of Internet traffic for most sites  
anyway, then stopping after DATA doesn't help as your OS will have  
likely received a socket buffer full of data, even if the application  
doesn't read it. So it might make you feel good, but it doesn't reduce  
the bytes coming down the line consequentially.


Mark.