The newest version of SmarterMail v6, uses a different file format for the mailing list subscribers. Previous versions use file type ".txt", the newest version uses the type ".csv". Importing subscribers from the previous versions with the default file type ".txt" will result in error:

Invalid File Type
To make your exported file work with SmarterMail v6 follow these steps:

1. Export your subscribers
By default a file "list.txt" will be saved to your local computer.

2. Open your subscribers file
In notepad open the list.txt file.

3. Add the EmailAddress identifier
At the top of the list of subscribers put the text "EmailAddress" with NO QUOTES.

4. Save the file
Save the file with the CSV extension like "list.csv", make sure it does NOT contain .txt after .csv by examining the file in explorer.

5. Import the list.csv file into SmarterMail v6.
This should work with no errors.