Be careful about opening Email
from unfamiliar sources. Today I had two emails from two different addresses (that I did not recognize) get quarantined by my antivirus that checks every email as it arrives in my inbox. Both had attachments whose names appeared harmless but if I had opened them my system could have been infected. My antivirus integrates well with my email client program (some clients don't allow such tight integration and some antivirus programs do not support it). Still when I receive email with attachments I am not likely to open the attachments unless they are from on of the several individuals that I know have their systems locked down as tight as I have mine. Remember almost any attachment type can be infected and be careful out there.
W.C.Update 2014-01-24 - Got another one today from another (unknown to me) address.