Charter email not working on MacBook Air Mail App

works on iPhone, but could not get it to work on MacBook Air using any of the settings Charter suggested. Finally found this that worked:

Enter your Charter email address except for the last letter, for example, xyz@charter.ne

This should cause an error and should display options to add the incoming and outgoing server name. Correct the email address, enter your password, incoming server: imap.charter.net outgoing server: smtp.charter.net

I got a message that the app cannot send your password securely on IMAP, but I clicked continue and it connected adding the account.. my iPhone and iPad mail apps work with the servers as mobile.charter.net