Hi, your device with the POP server is deleting emails after reading them. So when the inbox is viewed on the device with the IMAP server it is reflecting the server with the deleted emails missing. If you change your POP server, make sure that you have the correct port numbers in place. I have included a link that might help. I have also included a link with some information about both servers. Just remember that you can also change the setting in your POP server to save a copy of the email as well.
www.cox.com/.../email-server-settings.html
www.cox.com/.../cox-email-server-settings.html -Crystal