Re: SPF and bouncing

On Tue, 3 Apr 2012, Stuart D. Gathman wrote:
> If you don't accept DSNs, you don't get notified about mistyped
> addresses.  There is logically no way around that.  If you don't send

You can do what we're (TINW) already doing: use blacklists to terrorize
every mail admin into verifying mailbox existence in-transaction.  So typo
notification comes via in-transaction 5xx and not a bounce.

Sure, a bounce will probably be involved at some point, going from your
own smarthost to your own incoming mail repository.  But that's an
in-bailiwick bounce.  A spam can't pretend to be such a bounce, so those
*can* be given absolute right-of-way.

It's the bounce arising when someone else's backup MX can't deliver to
that same someone else's incoming mail repository that is the problem.

---- Michael Deutschmann <[email protected]>