On Tue, Sep 02, 2014 at 02:18:09PM -0400, Wietse Venema wrote:
> > Yes, the recipient and sender basic response codes are backwards,
> > this is a bug. It should/could be 521 for rejecting a nullmx sender
> > domain, but definitely not for a nullmx recipient domain.
>
> Reply codes 221 and 421 terminate an SMTP session. For consistency,
> reply code 521 ought to terminate a session as well.
Part of the problem is a bug in RFC 1846, which defines 521 correctly
for non-receiving systems, but botches the relay case (assumes
there's one recipient per envelope).
> Also, there is mangled text in section 4.1:
>
> [...] the address was mistranscribed or misunderstood, for
> example, to [...] or al...@examp1e.com rather than al...@example.com.
If you look closely, the first "example.com" domain has an "ell"
replaced by the numeral "one". Which is difficult to see with many
fonts.
> This is draft -08. Is that followed by AUTH48?
The -08 version was approved by IESG, and is now in the RFC editor
queue.
--
Viktor.
