Blank emails cannot delete

I have a quirky problem with my Netscape email. I have six blank emails in my inbox that usually show as unread and when I delete them one shows up in the trash folder but when you delete it (or even if you don't) and go back to the inbox you have six (6) balnk emails No subject, no message in the body and no return address. When you attempt to get header info it shows the last valid email's info that yoiu have viewed They all have the same date 1/12/69 and it concerns me even though I cannot directly link their arrival to a drop in computer performance. Thanks for any help and / or ideas