One trick spammers use is to send their email in HTML format and add a 1x1 pixel that is almost undetectable. The reason they do this is to verify if you have read the email. When you load the HTML email, it goes out onto the net to their server to pull the image down. Then they can tally the stats, and find out if their campaign is working. Additionally, you may not want to see the images they are putting in your email box. You can still accept HTML mail, but turn off the images, and only load them when you want to see them. Here is how to do it: Open 'Mail' Next, go to 'Mail -> Preferences' Now, choose the 'Viewing' Tab. Remove the check mark (if there is one) from 'Display remote images in HTML messages', and then close the window. Now, when you get email messages with HTML encoded in them, Mail.app will let you know that 'This message contains unloaded images'. you have to click the button to 'Load Images' to see them. After I click the 'Load Images' button, I can see the the pictures. You will need to be connected to the Internet to download the images.