MailChimp 

Connect with MailChimp right from within Microsoft Dynamics CRM using PowerMailChimp. 

Are you looking to send bulk emails out of your CRM, and track bulk email statistics back to CRM contacts, leads and accounts? PowerMailChimp is a MailChimp CRM integration tool that connects the powerful, robust, affordable third-party bulk email platform, MailChimp, with Microsoft Dynamics CRM. Use static or dynamic CRM marketing lists to send out bulk emails such as newsletters, offers, and more, all from within CRM. PowerMailChimp also tracks vital bulk email statistics, such as sends, successful deliveries, opens, clicks, bounces and unsubscribes back to individual CRM contacts, leads and accounts. This lets you see which of your contacts and leads opened the email, exactly who clicked on what link in your emails and if anyone unsubscribed. The statistics are super powerful, and the add-on is very simple to use. 
What it does: 
Send beautiful, rich HTML emails, without needing any HTML knowledge by using MailChimp’s robust template editor 
Use CRM information to create dynamic content in your templates, using merge tags 
Take advantage of CRM Workflows: 
Automatically fire off a response when a bulk email receiver clicks on a specific link, unsubscribes, opens the email, etc. 
Automatically add a bulk email recipient who shows interest in a specific product to a CRM marketing list 
Decide which CRM users have rights to PowerMailChimp, by assigning the PowerMailChimp user (or the PowerMailChimp read-only user) security role. 
Other PowerPack add-ons to further enhance functionality! 
Send surveys in bulk emails with PowerMailChimp and PowerSurvey 
Track web traffic of individual contacts and leads with PowerMailChimp and PowerWebTraffic 
Collect bulk email subscribers with PowerMailChimp and PowerWebForm 
View all bulk email statistics and other related records, specific to one individual contact, lead or account with PowerMailChimp and PowerOneView