Don't open, (if you didn't already) just delete or mark as spam.
If you don't recognise the sender's name, delete the email without opening it. It is a little known fact that email tracking systems know when you open an email (to read it or to immediately delete it). The sender can then identify the email address that have sent that email to as being a "live" address with a person who opens emails at the end. Simply they were trawling for "live" email addresses. you will be added a someone who has expressed an interest in receiving emails from them.