I had 4 messages like that to my GMail yesterday. Nothing else whatsoever in the messsage.
Message 41168.4 was deleted
If I don't know the person or place sending it, and actually have business or a personal connection to them, then it gets automatically deleted.
At least one nice thing about email junk mail, they didn't have to kill a tree to make it or give a mailman a backache to send it.