Hi RichB
Please change your settings to:
Host: smtp.cox.net
Port: 465
Security Policy: Use SSL/TLS on special port (legacy)
Host: imap.cox.net
Port: 993
Security Policy: Use SSL/TLS on special port (legacy)
Unless you are using different usernames and passwords for the IMAP and SMTP connections, there is no reason to select Use these credentials. Normally Use identity credentials works just fine.