The option to export an imported list is not directly available, however there are alternate options.


Option A: Select all email addresses in the list and paste into Excel 
This option can be utilized if the number of addresses in your list is fairly small and you want to capture all addresses
  1. Navigate to Email>Lists
  2. Click the Pencil icon next to the list in question
  3. Click View List
  4. Click your cursor in the upper left hand corner and drag your cursor to the bottom right corner
  5. After all the text is selected, click Ctrl + C to copy, then paste into Excel
  6. Repeat for other pages, if needed
Option B: Export emails from a sent message
This option can be utilized if the list in question has been used in a sent message.
  1. Navigate to Email>Messages
  2. Click the Reports icon of the email which utilized in the list in question
  3. Click the Recipients tab
  4. Click Export to .csv