Can your mail client prompt you, if you forgot to attach a file?

How many times you have received any mail which says that there is a file attached, but there isn't any file attached. The sender has actually forgot to attach a file. Also, how many times you have sent such a mail?

Ya, things like this happens. So what could be the solution? Can we have a mail client intelligent enough to prompt us about missing attachment? Is this possible?

Looking at the problem, I can see a very simple solution. It goes like this:

Prompt user before sending a mail WHEN
the mail content HAS WORD like 'attached' or 'enclosed'
AND
there is NO attachment attached

Also, this check can only be performed, when user wants his mail client to prompt about missing attachment, by explicitly setting the related option in mail client preferences.

Looking at the mails I have received without attachments, and sometimes the delay caused because of that, I strongly feel that having such a feature will be really useful.