attachment

A file (or group of files) that is included (or "attached") with an e-mail message. You can attach files through almost any popular e-mail program, such as Eudora or Outlook Express. Usually, this is accomplished by simply clicking the "attach file" button and then browsing through your computer system to find and select the desired file or image. Be careful with attachments, however, as they stay on your computer unless you go into your attachments folder and delete them. The best thing to do if you want to save an attachment is to open it, do a "save as," and put it in a folder on your computer. That way, you can routinely go into your attachments folder and delete them all without worrying about losing one you want. Never open any attachment you receive from someone you do not know; it may contain a virus.

An excerpt from an "E-mail Erin" question:
Dear Erin, I recently installed anti-virus software and all seemed fine except I could no longer see the attachements my daughter would send me of pictures of my grandson. Help!
Dear Help, Try doing this: Open your e-mail program and at the top of the screen, go to "Tools" scroll down to click on "Options" then click on the "Security" tab. There will be a statement in there with a checkbox next to it that says "Do not allow attachments to be saved or opened that could potentially be a virus." Make sure it is unchecked! Then hit "Apply" and "OK". Some anti-virus programs will automatically check that box when you install them, just be sure not to open any attachments from people you do not know.