?

Could you give more detail? Where are you seeing this option? If your asking how to set up a email program on your PC with Cox email then see here. 

If you have a Mac, you can follow this link. Although like many other companies, Cox is sorely outdated on the title (they say Mac OS 10.4 to 10.7 but Mac Mail is virtually the same instructions all the way up to the current 10.9.4. 10.7 literally came out years ago but Cox doesn't have good tech writers to keep their articles up to date, thus if you were to do a search on setting Mail up on 10.8.5 for example you'd probly come up with nothing)