That's horrible! I don't mind getting a printed letter but if I got a handwritten letter that I later found out was faked I would never, ever do business with that person again. Doing this means the very first step in an attempt to form a business relationship is an act of deception.
This is of course a classic submarine story: http://www.paulgraham.com/submarine.html
Every time I feel like I have come to terms with marketing people as economic actors they manage to plumb some new nadir.