SH**. D***. ***$**#.
When I was a kid, my sisters were told to put money in a jar every time they said a dirty word (I never said dirty words). Then the money would be used to help poor starving kids get fed.
None of the above is true. But we've all heard that putting money in a jar is a good punishment for using dirty words. And we all know that sisters are evil, especially older sisters. (For the record, mine are pretty good as far as sisters go.)
Drop the whole dirty word paradigm and just put a jar on your desk. Every time you send an email, put a quarter in, or even a dime. Heck, a penny. Force yourself to do this for a day. Make yourself think about every email you send.
Is it worth the quarter? If not, don't send it. If so, put the quarter in the jar and at the end of the week, send me your money. I'll use it to feed the poor children in my house who have to put up with me.
PS Add a quarter for every person you cc too. If it isn't worth a quarter, it probably isn't worth sending.
For other great email tips, Seth Godin has a bunch. He's the only guy worth reading other than me...