I noticed no cox.net emails were listed on the iPhone 5s, but are still there on my rMBP. I sent a test email to cox.net from icloud.com, then replied back and forth. On the rMBP all messages are displayed. On the iPhone 5s, the messages to cox.net are initially received, even allow my to reply, but within a minute vanish completely from the iPhone. Cox.net is a POP account on the rMBP, but appears as an imap account on the iPhone. It was working fine before the upgrade to iOS 8. I tried creating a new cox.net account and get the same vanishing emails.