I, like many others, have been following your discussions with great interest and admiration for the respectful comments and support most people are giving.
I wanted to add something I may have missed in all the posts. My iMac mail account seems to be the "Papa Bear" - whatever I do there translates out to ALL my other devices -- If I read a message on my iMac desktop, for example, All my other iPhone, iPad, MBAir and older iMac desktop show it read. Here's the glitch. If I read an email on my iPad, it will show it read only on my iPhone. All computers are running Mavericks, and all are up to date.
MBAir: Now, if I DELETE a message from my MBAir, It will delete the message on the iMac desktop. It will NOT show messages read, though.
iPhone: Same goes for the iPhone -- If I DELETE messages, they get deleted from all. But if I READ messages, nothing changes and neither of the computers shows "read" except the iPhone and the iPad.
iPad: The iPad and the iPhone seem to be synced -- it's so very strange!
Thanks for all the chatter about this!