Importing CSV into e-newsletter, is there a secret?

What's the trick here? I've created and imported dozens of CSV files into databases, other plugins, etc. and I can't get this to work.

Is there a sample of what it's supposed to look like?

Is there a limit?

Have tried it 14 different ways, with semicolons, with commas, with first names & last names and without and the flipping thing is merging all of the fields. I haven't had a single success in importing. I've tried it using an Excel CSV and even tried exporting the content into a text editor. I've cleaned every line of code to make sure I don't have any extraneous spaces or bad characters.

Can you tell I'm a little frustrated? Something that should have taken 5 minutes, has now taken 1-1/2 hours.