Sure, in addition to this though. IP reputation comes from spamhaus.org and the like and implemented in spamassassin or something similar, at SMTP(ish) level.

Sure, in addition to this though. IP reputation comes from spamhaus.org and the like and implemented in spamassassin or something similar, at SMTP(ish) level. What you're talking about there is SPF/DKIM etc, which is an anti-spam measure but not IP reputation :)