. . . delete it without opening or reading.
My system seems to have been hacked, and fake emails from "me" have been going to people on my contacts list, containing links to penis-pills sites and worse. (Such as malware sites that will try and infect YOUR computer too.)
The good news is that the malware isn't smart enough to generate a fake subject line to go with the fake email.
So, Rule of Thumb in this instance is: If an email is lacking a subject line, delete it unread.
My standard security software (Trend Micro) didn't catch the bugger whenever it got into my system (*grump* *grump* *grumpety-poo*), so I'm curently running additional software to try to find and remove the culprit.
When the Revolution comes, and the triumphant mobs thrust me into my rightful position as Semi-Benevolent World Dictator, hackers will be executed in slow, cruel and appropriate ways.
UPDATE 10/23/10: The additional software I ran reported my system as clean, but it didn't report actually finding or removing anything. But nothing new in the line of fake emails has been reported to me, and nothing I've supposedly sent to myself (I got some of those too) has shown up in my email queue, for the last several days, so -- fingers crossed -- hopefully the problem has been eliminated. Still wish I knew where the problem originated, though.