After I open and read emails some are randomly deleted. They are still on Windows Mail on my laptop, but not my BB Bold. This is a work email address and very important to me. I do not have this problem wtih my personal Yahoo email.
Also, some emails that arrive on my laptop early in the morning never make it to my BB Bold.
You might try to resend your service books. That might get your email going for you. Also, from your device, dial *228 and select option 2 to update your PRL on your device.
To resend your service books, go to Email Settings and press the Menu key (to the left of the trackpad). Then, select Service Books and select Send Service Books. Hope that gets you going.
Ps: Got to thinking since you have a Bold. In case you have OS 6 software update on your device, select the All tab and open the tray. Select Setup and select Email Accounts. Then, press the Menu key and select Service Books and then select Send Service Books.