Look for an “all mail” folder. If it has any unread emails in it, clear and mark that mail as read. For me, once I did this my iPhone updated, and the problem is corrected! For the iPhone, ghost messages disappeared by disabling mail, then turning off, then back on and then re-enabling Mail.
When you call a dead phone does it ring?
Answer: A: With a dead battery it should not ring but it should go to voicemail directly.