In most cases, embedded images in email are just as they appear: photos from friends and family and other folks you know.

But sometimes, images in emails can be used to spread a virus or other malicious code. This malicious code can sometimes be hidden in an image that has a filename ending in .jpg or .gif or .exe. So it’s wise to be extra-cautious when it comes to opening image files. 

The first step in protecting yourself is to make sure images emailed to you do not automatically download (just as you have it set right now). Automatic downloads are a surefire way to allow malicious code onto your computer. The fact that you have to take an extra step and choose to view the image will give you control over which files enter your computer.

The second step is to determine whether you know the sender. If the sender is a stranger, don't download the image. If you do know the sender, contact him/her and make sure that the email did in fact come from him/her before you download the image file.

Third, many email programs, such as newer versions of Microsoft Outlook, now allow you to preview an image in the email instead of downloading it onto your computer. Different email programs have different ways of letting you preview attachments, so search the help menu of your email program for attachment preview. Previewing gives you a look at the image without downloading and potentially launching malware. If it doesn’t appear to be an image, don’t download it.

Lastly, most email providers have strong spam and virus filters that will keep image files containing viruses or other malware from reaching your computer. Make sure your security software includes such filtering tools.