download Thunderbird email client, have it connect to your cox account, then select all email, and save as, it should save all of the selected emails as a standard .eml file with a filename and date-stamp of received time in a nice way, you can then delete all the existing email on your account. you will still be able to use Thunderbird as the email client for cox, and how many other email accounts you have. since i have upwards of 15 email accounts, its nice to have them all in one place.
If you setup thunderbird as IMAP, you will STILL need to archive the email into an archive folder, OR, it won't be downloaded to the computer, and when you delete all the messages they will be GONZO, unless you setup thunderbird as POP, then it will ONLY download the INBOX folder from Cox to the computer.
