I work at MailChimp. The answer is nope.
As you work at MailChimp, it would have helped if you would have given that detail.
Our approach to dealing with fuzzy spam is here: http://blog.mailchimp.com/project-omnivore-declassified/
an update was posted here: http://blog.mailchimp.com/update-on-omnivore-new-3-strikes-r...
Probably shoulda brought that up in my blog post (it's usually the first question techies ask), but it's something our customers are pretty familiar with, so I left it out.
ETA: Also see bjonathan's comment at http://news.ycombinator.com/item?id=2170619: Amazon, which probably offers something closer to "server and bandwidth", is much cheaper.