Outlook and server issue

Have a couple issues with email.  First, when I sign into email on the server, I receive TWO of every email! I have tried chat for help many times (going on for over a year) but to no avail.

Second, I use Outlook so when emails are downloaded I get the same issue - TWO over EVERY email!. I use the "clean up folder" on the Home tab to resolve this every time I open Outlook but have to use it for EVERY folder.

Third, when I download emails to Outlook, they still stay on the server. They used to be deleted on the server once downloaded to my computer but i can no longer find the tool in Outlook or on Cox email.