If I wrote a mail client....

If I wrote a email client, it would do a sanity check on dates before sending messages. I had the date time set wrong on my machine recently and sent a message out on July 18th (it's presently July 2nd) Now everyone who received that message is going to be annoyed by having it sort to the top (or bottom) of their inbox until July 18th actually rolls around (unless, of course they actually keep a clean inbox ;-) )

And while I'm at it, my mail client would scan the text for the words "attachment," "attached," "attaching," etc. If any of these appeared but there was no attachment, my client would prompt me: "Did you forget to attach a file?"