First Create a new list by clicking on Create List on the Dashboard, or entering the Contacts page and click on New List as shown in the next two pictures.
You may also pick an existing list mentioned in the Contacts page by clicking the listing there.
Click on the Import Contacts button next to Contacts.
Click on Upload CSV file button on the next page and choose the file from the file browser or simply drag and drop the CSV file on the upload section. This will upload the CSV file to SendX and into the chosen list.
After that you should see contents of CSV file and drop down against every column in CSV. So you have to do mapping by selecting appropriate columns against email, name, company etc. Once confirmed, click on Submit to import the right columns into the list. Please note that Email is a necessary column to be added here.
Once completed you will get an email about number of contacts that have been successfully imported as well as the ones that were either duplicates or were invalid.
And that's it! That's all you need to do to import an external list into SendX!