ATHG is an unmoderated listserv, so what arrives gets sent (unless the listserv manager detects that it is SPAM, i.e., commercial email sent to a vast number of people offering scams on how to get rich quick, etc.). Although I have a program that automatically updates my anti-virus software monthly, I open attachments from only people whom I know and urge everybody else to do the same. My main problem comes from students who send papers from computer labs, notoriously virus-ridden places. I confess that I don't know how anti-virus software works; I do know that I occasionally get email with the picture of a bug next to it and instructions to delete without reading.