Would you like to link Magento with Mailchimp?
- Create an account at http://www.mailchimp.com
- Download and install the MageMonkey plugin from: http://www.magentocommerce.com/magento-connect/mage-monkey-mailchimp-integration-4865.html
- Grab the API key from MailChimp. Login -> Account -> API Key -> Add a Key
- Insert the API key in Magento under System -> Configuration -> Clients -> MailChimp -> API Key