most of our emails need an attachment like an infomemo or a NDA. We use the same email template but different attachments. Therefore it is not possible to integrate the attachment in the email template.
Unfortunately sometimes we forget the attachment and send the email naked. So it would be great to have something like a checkbox in the template designer that there would be a warning if you send your mail without an attachment (like it warns you when you send an email without a subject).
My workaround is "ATTACHMENT" in big red letters in the template that you have to delete by hand.
As you can see this is neither smart nor beautiful ;-)