----- Original Message -----

> From: "Murray S. Kucherawy" <[email protected]>
> To: "Scott Kitterman" <[email protected]>
> Cc: [email protected]
> Sent: Tuesday, December 23, 2014 10:32:44 PM
> Subject: Re: [dmarc-ietf] Jim Fenton's review of -04

> On Mon, Dec 22, 2014 at 10:44 AM, Scott Kitterman < [email protected] >
> wrote:

> > There was a recent thread on postfix-users about DMARC rejections when
> > there
> 
> > are DNS errors that caused me to review -08 to see what it says on the
> > matter.
> 

> > At the end of section 5.6.2, it says:
> 

> > Handling of messages for which SPF and/or DKIM evaluation encounters
> 
> > a DNS error is left to the discretion of the Mail Receiver. Further
> 
> > discussion is available in Section 5.6.3.
> 

> > My reading of 5.6.3 though is that it only discusses DNS errors in the
> > context
> 
> > of failing to retrieve the DMARC record. Any discussion about handling DNS
> 
> > errors for SPF/DKIM seems to be missing.
> 

> Yes, DMARC punts on what to do when SPF or DKIM encounter transient failures.
> I imagine that's because those modules would arrange to temp-fail a message
> that has that problem. I suppose my experience is that messages don't even
> get to the point of DMARC evaluation when that happens, because the message
> has already been temp-failed.

As SPF (and DKIM) can report a message with the status tempfail, it means the 
message is not necessarily tempfail (bounced). 

> If you think about DKIM and SPF as being part of a layer below DMARC, then
> I'm not sure it's wise of us to be making any kind of normative statement
> about what to do when the lower layers fail.

> What do you suggest?

I think we should recommend something here, not sure if it needs to be 
normative. We do say to ignore the SPF policy when p!=none, though I think we 
can be normative on the lower layers. I see 2 options here: 
1)tempfail the message is either SPF and DKIM have a tempfail status 
2)tempfail the message if both SPF and DKIM have a tempfail status 

1) is my preferred and is aggressive, therefore not sure people will like it. 
I'll settle for 2) 

As explained in another post, I'm worried I can run a DNS attack (or just a 
self inflicted DNS bad config) and get DMARC to reject emails it should have 
accepted (has the DMARC policy in cache, but cannot assert SPF and DKIM). 
_______________________________________________
dmarc mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/dmarc

Reply via email to