iPhone 4S sending old push mail notifications when locked
I use Gmail on my iPhone 4S and it keeps sending old push notifications. I have only noticed this happening when the phone is locked.
If the phone is locked and a new mail arrives, it will vibrate and show me a preview. The following keeps happening: the phone will vibrate, then show me a preview of one or more mails received several days ago.
For example it just vibrated and then showed me previews of five emails from Monday (it's Thursday today). I had already read all of these mails and had deleted some of them.
I am using an iPhone 4S with iOS 6.0.1 (10A523). It's a new phone, rather than an old phone with a new problem.
There is no "repeat alert" setting for mail like there is for SMS, so this isn't the cause. And the emails aren't new/unread, so the phone shouldn't think it needs to tell me about them again.
It is really irritating because it makes me think I have a new mail, then shows me ones I've already seen.
If all else fails I will try deleting and re-adding my email account but I would really like to know if this is a known issue and/or anyone can suggest a fix.
iPhone 4S, iOS 6.0.1