The mailing list for listmasters using Sympa

[Steve Shipway <address@concealed>]

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.

 

Steve

 

Steve Shipway

address@concealed

 

 

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