This is exactly what I assumed caused them to make this decision.
Who knows, a lot of Mailchimp employees might even really like blockchain tech, or be intererested in ICOs, but at the end of the day, if serving ICO/blockchain mail results in lots of emails marked as spam, it puts their whole business at risk.
Also, they could be held legally liable (or at least: party to a suit that suggests their legal liability) that they don't want—it's risk mitigation. But the question is: What of the other ostensible scams on their platform?
