When uploading a CSV to a Custom Segment keep the following in mind:
There will be no indication that the upload has completed. Simply click "Browse" find your file, and then click "Save and View" from the Segment.
You will receive an email once the upload is 100% complete or if there are any errors.
When creating your CSV:
The CSV file must be formatted with "Email" as the header text and each email address in its own cell in the same column, as seen below:
Any configuration outside of what is seen below will result in a mal-formatted file and will not work.
