[swinog] Broken SPF Check implementation in Microsoft Exchange Forefront?

Hellou

Today, I discovered, that emails whose envelope sender matched the DNS SPF record, but whose From: Header did not (like after the envelope sender has being rewritten by SRS) were rejected by a hosted exchange server provider.

I got in contact with that admin and he told me that this was the way the SPF check works in the Microsoft Exchange Forefront Server.

Well, according to the RFC 4408 only HELO or MAIL FROM are being considered for SPF. Not the From: header. Is there anyone out there who can confirm, that Microsoft Exchange Forefront Server realy has such a broken SPF implementation. Or did the exchange admin just misconfigure his server?

Mit freundlichen Grüssen

Benoit Panizzon