Hello 209672,
If you are interested in free email I recommend switching to Gmail.
If you are interested in privacy I recommend switching to StartMail (First year at $29.94 | Renews at $59.88)
If you are using a mail client such as Thunderbird Or Outlook then migrating your mail will be as easy as connecting your new mail account then dragging and dropping old emails to the new email account.
You should configure an auto mail forward from your old Cox account to the new email address you configure, tap or click here to see how.
You should also configure the Vacation response on the Cox account to inform people who email you of your new email address, which is also listed in the article above.
If you do not want to deal with all of the above, then I would recommend just transitioning to the new Yahoo mail, then you won’t have to deal with a new address as you continue using your old address.