MailChimp is a widely used Mailng List delivery and support service.
http://www.mailchimp.com
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Get access to data on 3,268,896 websites that are MailChimp Customers. We know of 1,029,717 live websites using MailChimp and an additional 2,239,179 sites that used MailChimp historically and 601,600 websites in the United States.
Get a list of 3,268,896 websites using MailChimp which includes location information, hosting data, contact details, 1,029,717 currently live websites and an additional 943,849 domains that redirect to sites in this list. 2,239,179 sites that used this technology previously and 601,600 websites in the United States currently using MailChimp.