You score 7/10
M$ STRONGLY bar "the reverse-DNS PTR records". Definitely not needed on voyage. That is unless I have misunderstood all their emails.
"We reviewed your SPF record and note that it includes the "ptr" or reverse DNS lookup mechanism. The specification for SPF records (RFC 4408) discourages use of "ptr" for performance and reliability reasons. This is especially important for Windows Live Mail, Hotmail and other large ISPs as a result of the very high volume of mail we receive each day. We highly recommend you remove the "ptr" mechanism from your SPF record and, if necessary, replace it with other SPF mechanisms that do not require a reverse DNS lookup"
Actually make that 2/10 - bold is where you are right. I'd hazard a guess you're
sending mail out from a DSL originating IP range, to an SMTP server that itself is victim to being marked as a spam sender by the RBLs on a regular basis, and you're sending out mail content that possibly appends dodgy URLs in the signature, or has crap like Incredimail in the body.