DKIM Deployment

[Jesse Thompson <>]

So, I've been playing around with the new DKIM verification feature in 
PureMessage.

One thing I notice is that all signatures from Yahoo and Facebook are 
failing, and mostly succeeding for other domains, including Gmail and 
Paypal.  Not that I care that much about validating email from Yahoo, 
but I wanted to know if the problem was on my end, or their end.  Surely 
Yahoo is correctly signing their mail!?

So, I did some testing with the auto-responders listed in the 
"Interoperability Testing" section of http://dkimproxy.sourceforge.net/

It appears that Yahoo's signatures fail for some of the autoresponders, 
and succeed for others.  Also, it appears the subsequent tests to the 
same auto-responder yields inverse results (which I can only assume has 
to do with solar flare activity).

So, basically, Yahoo's DKIM signatures are totally inconsistent.  Is 
this just Yahoo (and Facebook)?  If DKIM is this unreliable for other 
senders, I don't know how it can be useful for things like whitelisting.

Jesse

--
  Jesse Thompson
  Division of Information Technology, University of Wisconsin-Madison
  Email/IM:

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