Step 1: On the right hand side you can see List option in LIST MENU, Click on list…
Step 2: You can just create List name first and fill all mandatory details .
Step 3: Then click that list name, it will shows some option ..
After Saving changes the details you can see the page like below screenshot.
Then click List You should see your created List(s) like this..
Click Overview Option on right side of the page
Step 4: Click ” Tools” Option And select Import Option then import your CSV/TXT file ..
You can Import CSV/TXT File. If you choose CSV File your page like this..
Your selected CSV file must contain “Email Address” Header.
If you choose TXT File your page like this..
Your selected Text file must contain “Email Address” Header.
After Upload the List you see the below page.