1.open your e-mail plugin.
2.find and click on "export"
3.select the desired location in your computer to store the mailing list data (.csv file).
1.now log onto www.mailchimp.com
2.sign in to your account
3. Go to List
4.create a new list.
5. fill the required information to create the list.
6. click on import subscribers
7. Browse the path of the stored list.
And you are done!