I recently reset all settings on both my iPhone (5) and iPad (Air) and set them up as new devices, no settings carried across, nothing. I set up my mail accounts on both in exactly the same fashion as I always have done and have no trouble sending/receiving email.
The problem is, I have a few emails on my iPhone that are marked as unread, yet on my iPad and on my Mac (MacBook Pro 13" Mid-2010) they are marked as read. Why is this? Even if I synchronise my Mac with the server (which is iCloud, btw), the read status doesn't change on the phone, but it does on the iPad.
What I want to know is why the status was updated on the iPad and not on the iPhone when they were both set up in the same way at (roughly) the same time? I know I could manually mark the emails on the iPhone as read, it wouldn't be a problem, I just want to understand the cause of this behaviour first.