people send email and think they go through and I do not receive

This is just a stab in the dark...but do you only use Cox webmail or do you also have email clients (Outlook, Thunderbird, Apple Mail) installed on other devices?  If you have other devices with email-client software and configured as POP, those devices could be downloading your email from the server.  Of course, this would assume these clients are only online from "time to time."