Here's my free idea: An email service provider (ESP) that caters specifically to B2B and B2C newsletters (I'm thinking 100k to 10mil+ messages a month). It's crazy that this doesn't exist. MailChimp and similar have pricing that does not scale up. Meanwhile MailGun and similar do not have the analytics or list management that publishers need. They are geared towards transactional messages, not newsletters. Lyris/Emai…
http://clickmailmarketing.com/
and they seem to be happy with them.