Yes. If you are using Outlook to access your charter.net email account, you need to be using Charter ISP since Outlook initiates connection to the charter servers, the one with the POP and SMTP servers are charter's servers. If you are connecting from another ISP, charter will refuse the connection.
Your option then is to use a web browser to access charter emails when you are away from home where charter is the ISP.
If you want to use Outlook, you can add other emails though, like the emails provided by the ISP that you are currently using. Hotmail and Gmail accounts can be used with Outlook also, but not Yahoo if it is a FREE Yahoo account.
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