how to block email without sender address
I am receiving many emails with one line of seeming useless info "Making hummingbird wine 6607" The email contains no sender address. I have them going to my JUNK mailbox, but am tired of having to continuusly having to eliminate them. Is there any way to truly block them?
Thank you.
Also what are they really?
iMac, OS X Mavericks (10.9.4)