Unlayer is a drag-and-drop email editor that allows you to quickly design email templates from scratch or with the help of hundreds of professionally designed email templates for Mailchimp. By using Unlayer, you can customize your own responsive HTML emails and export the messages to Mailchimp to share them with your email subscribers.
To send an email template to Mailchimp, use the Unlayer editor to create your email campaign. When you are done designing, you will be taken to a page with campaign details. Click on the "Export Campaign" button and select "Push to ESP" from the menu of options.