They clearly have the ability to flag "automated" messages, which you're (Box, not Greg) now saying is the issue. Just flag them as automated in the queue.
"SELECT * FROM queue ORDER BY flag, timestamp"
Presto, all non-automated messages go before any non-automated messages. Bandwidth problem becomes a non-issue. Buyers and senders of automated messages decide whether the delay makes the service unusable or not.
Choosing specific senders and specific messages to completely block takes them out of safe harbor provisions.