The mailing list for listmasters using Sympa

[Erik Olson <address@concealed>]

On 2014-04-08 02:42, Steve Shipway wrote:

SIDF is Microsoft’s … improved … version of SPF, often erroneously called SPFv2.0.  See here http://en.wikipedia.org/wiki/Sender_ID

 

While SPF validates the Envelope Sender address against the source IP, SIDF allows the SPF record to specify checks against the From and Sender addresses as well.  By default, it checks against the PRA, which is who the messages claims sent it.  This would normally be the From address, but if there is a Sender it should use that.

 

It is annoying that you don’t get a better analysis from Yahoo as to why the message is being rejected.  It seems that they are doing SIDF verification but ignoring the Sender header?  You might like to verify that your mailing list is definitely adding the Sender header and not stripping it out for any reason.

Checked, and sympa is definitely changing the sender to "address@concealed".

Truth be told, I'm not sure yahoo is doing SPF or Sender ID.  I can clearly see it doing DKIM, calculating the signature based on (amongst other things) From:, Subject: and Reply-To;
Since our mailing list is rewriting the Reply-to to keep things on-list, and also rewriting the Subject, DKIM is more assuredly failing.  But I don't see any TXT or SPF records when doing digs on yahoo.  So I suspect mail is getting rejected entirely on the DKIM mismatch or omission.

  - Erik

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Erik Olson
Proudly joining 21st Century e-mail in 2013