I'm using the email app as I have a Yahoo account. I have it set to check every 5 minutes, to notify upon retrieval, and to vibrate upon notification. I bought this phone off Craigslist but it was new in the box. I rebooted it once and got a notification for the next email I got but no others after that. I also downloaded a Yahoo mail app and again, I got the notification for the first email, but no others after that. What can I do to get notifications?