IPv6 isn't SMTP

Wed Mar 26 04:50:29 UTC 2014

>> But, as always, I'm not holding my breath.
>
>Is spam fighting really about SMTP?  Or is it about abuse of the 
>transport layer by (among other things) the SMTP?

I don't think that your typical spam recipient cares how the spam got
into her inbox.  Anyone who has any familiarity with large scale mail
systems knows that the only way to have any hope of effective spam
filtering, in any medium, is to combine all the clues you can get.
For mail, the source of the message is a highly useful clue.

R's,
John