Hi,
We are using Exchange 2010 SP2 with Edge Transport, when I send an email to Gmail address in the email header on Gmail there is an SPF error:
Received-SPF: fail (google.com: domain of prvs=46535EDF8F=user@domain.com does not designate 2001:0:5ef5:79fd:37:76ab:60eb:8e8d as permitted sender) client-ip=2001:3:2ef1:79fd:32:76ab:60eb:8e7d;
Authentication-Results: mx.google.com; spf=hardfail (google.com: domain of prvs=46535EDF8F=user@domain.com does not designate 2001:3:2ef1:79fd:32:76ab:60eb:8e7d as permitted sender) smtp.mail=prvs=46535EDF8F=user@domain.com
I'm sure our SPF records are correct, I' ve also tested with Yahoo mail and there is no any error message in the header.
We have disabled IPv6 on Edge Transport NICs as wel but it doesn't resolve the issue.
Any idea?