[EAI] Re: SPF and DKIM

[Frank Ellermann <nobody at xyzzy.claranet.de>]

abel wrote:

> Do we discuss those more ?

For SPF I consider a separate draft.

>     A example in downgrading :

>>>ehlo twnic.net.tw
>>>mail from: <UTF8 at twnic.net.tw>  ALT-ADDRESS=ASCII at gmail.com  # EAI-aware
>>>rcpt to:<UTF8 at other.domain>     # non-EAI-aware

> when the downgraded mail transmits , if other.domain run SPF check, we can
> pass in SPF helo check ,but fail in SPF  sender check (ascii at gmail.com) if
> gmail.com SPF records with -all unless gmail.com adds SPF for us,
> but it seems impossilbe to do that.

Downgrading is actually the simple case.  Of course using different policies
for the UTF-8 address and the ALTADDRESS would be unwise (putting it mildly).

A simple way to guarantee no nonsense is to use the same domain resulting
in the same policy, e.g.

MAIL FROM:<martin at dürst.example> ALT-ADDRESS=martin at xn--drst-Ora.example

It starts to get more interesting without downgrading if the local part
uses UTF-8, and the result has to be reported in a Received-SPF header
field.  And of course no SPF implementation already supports the IDNA
magic to deal with internationalized domains, but in theory that's a
solved problem (okay, I lurk on the IDNAbis list, s/theory/THEORY/ :-)

Frank



_______________________________________________
IMA mailing list
IMA at ietf.org
https://www1.ietf.org/mailman/listinfo/ima