John Carter springs this question, "Have you ever noticed that when you send an e-mail with an attachment, it shows up in your Sent folder with the attachment seemingly replaced with the words 'Missing Plug-in?'
" A few weeks back, some advice was given out to supposedly protect you from a Java related virus. The advice said to open 'Java Preferences' (this application is in /Applications/Utilities, or just search for it with Spotlight) and uncheck the box in the General tab: 'Enable applet plug-in and Web Start applications.' Unchecking that box causes your attachments to disappear from your e-mail in the Sent folder and maybe cause you to think that the attachment didn’t go through.

"To see your attachments in your Sent folder again, make sure that the box is checked and then click on the button 'Restore Defaults.' All will be fine again. As for the Java related virus warning, both Java and Apple have pushed updates that you should have installed, and those updates will protect you - until the next new virus comes along."

But John, we asked, "what about the Safari Preferences"?

Here's John's reply: "Not the same. What you show is for Safari, not Mail. Since I have installed all the latest Java and Apple updates, I have 'Enable Java' box checked in Safari Preferences as well. But that setting does not affect how Mail works."