Heh... I'd been meaning to write something like this, and if I ever get off of my duff and write a full-featured mail handler, it'll have it.

Solving the attachment issue:

The Attachment Scanner plug-in is the solution to the "no attachments attache" problem. Once installed, the plug-in sits quietly in the background until you press the Send button. When you press Send, the plug-in goes to work, scanning your text for "attachment" words, and making sure that there's actually an attachment attached if such words are found. If there is, nothing happens -- your message is sent as you would expect. But if you try to send a message that references attachments, without actually attaching your file, you'll see this instead: [alert:Message Has No Attachment]"