One of the most frequent requests that you find on the internet is to import an external list within the CRM and simultaneously create a marketing list without creating duplicates.
The Microsoft Dynamics CRM platform doesn’t have this feature, you must use a workaround to be able to import the external list, but unfortunately you can’t avoid creating duplicates.
PowerAddon is the first suite in the world, integrated into Microsoft Dynamics CRM to have a tool that helps Digital MarketingProfessional to import within Dynamics CRM external list thus avoiding import duplicates. PowerImport is a very powerful tool, that has an engine that is able to import lists from 500,000 record at a time. The tool allows you to define from time to time the structure of the Excel spreadsheet to import, without having a fixed structure.
Here you will find my full post on how to use this tool to import your contact list from an Excel sheet with no duplicates: http://goo.gl/TBjDV4
Have a good day