Last evening my iPhone began to exhibit very odd behavior. Every few minutes (whether awake or asleep) a dialog appears saying that "You got a mail." I've posted a screenshot below. (For those who don't read Japanese the text above "You got a mail." translates as a "A message was received.")
Sometimes I must press dismiss multiple times before the screen disappears and the lock screen is displayed. I have tried in vain to locate an application which is causing these messages. I have also disabled notifications from Facebook, Mail, etc. At present I think that this might be some sort of bug or exploit.
I've restored by iPhone using a recent backup. After the restore, After syncing apps the message remains. I also reset to factory and even without my apps the message remains. It also seems that the message does not appear when my iPhone is in airplane mode.
My question is, has anyone else encountered anything like this message?