Multiple copies of e-mails

I use Outlook 2016 as my mail reader. I get e-mail via POP3 from pop.cox.net. I have four different e-mail accounts with Cox. For the last 4 or 5 days, I have been getting multiple copies of most of the e-mails sent to me. I will receive an e-mail, then hours or even days later, I will receive another copy of the same e-mail (same header info, not a new e-mail with same contents). On some e-mails, I only receive one copy, but on others I have received up to 5 copies over the course of a few hours. I have gone to the Cox Webmail Inbox. There is usually only the last e-mail or two that I have received. The e-mails seem to be getting deleted fairly quickly. In Outlook, if I click the "Send/Receive All Folders" button, it sometimes gets another copy of an e-mail (which is not one that still shows on Webmail), but other times (more often) it doesn't receive anything. But 10 minutes later, I will get another dupe e-mail. None of the settings in Outlook were changed.

Any ideas???