Receiving Blank email messages in Yahoo account

I keep getting blank email messages in my in box on my Yahoo account on my IPhone. The messages are from "(No Sender)" w/ "(No Subject)" and the date sent is 12/31/69. I can't open or read the messages either. The body of the email on the preview screen is "This message has no content". Also, I keep getting new message, legitimate ones, and they don't appear in the in-box.

Can anyone help?