My friend just ignore those emails and set outlook to open everything (emails and new messages) as plain text, by doing this you'll start to feel sorry for viruses like jammer (which a slammer rip off) and others like it cause they can't infect you whatsoever, however IF YOU ARE INFECTED I'D GET AVG Antivirus or Norton Antivirus IMMEDIATELY!!

P.S. Don't forward these emails whatsoever NOT EVEN IF SOMEONE CLAIMING TO WORK FOR SYMANTEC OR MACFEE TELLS YOU TO DO SO!!!
The real Symantec Corporation doesn't forward emails nor ask's it's customer's to do so either!