My wife updated to the latest version & promptly lost all emails between July !5th and August 22nd. I emailed BT Yahoo Mail,they phoned me
" People have been having some problems such as losing email content, this is caused by the Yahoo Server Update,if you change back to Mail Classic you should not have any more problems"
Well that was a great help to my wife who now has no evidence of any of her business emails between the dates July15th/August 22nd