Spam of All Kinds: Dealing with Online Abuse was mostly a dense rundown of the state of current email spammer and anti-spam practices. Steve Champeon emphasized the incredible load put on email providers by spam, most of which is invisible to users.
I have been moderately surprised for awhile that whitelisting hasn’t become more or less the default for email. I think Champeon’s “things not to do” slide indirectly said not to use whitelisting (it said to not transfer burden to other legitimate users — most whitelisting services make users not on the whitelist jump through some hoops to get on the list).
A question I would’ve asked if the session didn’t run out of time: Why hasn’t spim become a major annoyance? I accept instant messages from unknown parties but almost never get spim.