mail account issue

I made the switch recently. My email is from my cable carrier. I know my incoming should be pop.charter.net my outgoing smtp.charter.net my password is correct and my user name is correct, yet the automatic set up and manuel set up for email accounts still cannot connect.

My network connection is fine (did a diagnosic).

Please help.

Thanks,
Wondering if I should download Thunderbird?

Adding a New Account in Apple mail - Charter Communications

There is the step by step, remember that with charter you must enter you full email address as your user name, not just your username.