This post started in 2010 and I am amazed that people are still having the same problem now (October 2013).
I am referring now to an iPad Mini which I bought in January 2013, which did not have this problem until about the time that Apple released their new operating system about a month ago.. It is currently showing 35 unread emails and rising.
I spent 4 hours talking to an Apple help line yesterday who knew his stuff and after two complete resets it did not resolve the problem. He concluded that the problem lay with the provider. In this case Yahoo. This opinion was reinforced to him because my iphone, with an earlier version of the operating system was experiencing the same problem and therefore could not, in his opinion be caused by the new operating system, which sounds logical..
I then spoke to a top tier Yahoo/Sky help line at length who again knew his his stuff. After a great of experimentation, he concluded that there must be unread mail in my folders, which have been read, but were regarded by the software, as unread. I went through each folder and not only checked that there were no emails marked as unread (with the little blue dot against them), but opened each and every email. The number of unread emails stayed exactlly the same.
He advised me to download the Yahoo Mail App and use that in preference to the ipad mail, which I did and I am now using that. Unfortunately the Yahoo Mail app does not indicate whether a new email has been received without opening the application, so that does not really advance the situation..
The Apple representaive told me that he would report the poroblem to their developers. The Yahoo representative did not really come up with a final conclusion, except that he believed it was a problem with the iPad, did not sound too encouraging as regards the matter being investigated any further..
One of the bits of advice I was given at the first tier Yahoo helpline was to ensure that on the server the line relating to pop and forwarding was checked ' dont allow download spam mail'. This does not apply in my case because I am using imap and there is no similar option for imap.
It's high time Apple and the internet providers, particular Yahoo, got their heads together and came up with a fix for this problem because it is obvious that countless people are having the same problem.
Does Apple ever take any notice of these poosts, or is it just hot air?. Sounds as though that is the case if it has been going on since 2010.