If you want to use your COX email on your email client, we suggest you first try adding it using the Automatic setup method. You won’t see a direct option to add COX email however the automatic setup can be done by selecting Others in Add Account. The email app will configure your account as IMAP and you won’t need to enter any settings manually.
In case the automatic setup doesn’t help, then you can configure COX email settings on your own with the help of the below COX email IMAP settings.

Incoming Server (IMAP) Settings
Select IMAP in Account Type.
Now enter imap.cox.net in the Incoming Server hostname.
Enter 993 in the Port field.
You need to enter your complete COX email address in the User Name field.
In the Connection Security, select SSL/TLS.
Select Password in Authentication.

Outgoing Server (SMTP) Settings
Enter the Server Name: smtp.cox.net
The SMTP port is 465
Enter your complete email address in the UserName field.
Select SSL/TLS in Connection Security.
Authentication: Password.

https://www.emailsupport.us/blog/ways-for-cox-email-settings-on-iphone/