if you cut the dummy letter ammount in half, that should be much more manageable. 5-7 should be plenty . I just realeased my last one for a while (most likely) which you can find here, if you want to use it to help make your own. http://www.wc3sear.ch/?p=Spells&ID=770
First off, typing "AHHHHHHHH ect." doesn't reflect well upon yourself, but I understand your frusteration completly.
The reason why it doesn't work is an extremly good reason. Let me take some time to explain it to you, because I'm sure you don't want a one sentence answer.
Blizzard is concerned that people would take advantage of this feature, and send viruses and other malicious scripts to other computers, causing a pretty big problem. While most people would use this feature to greatly enhance their games, it would not be worth the risk. I have seen posts about this before on other forums.
Well, I guess that wasn't long, but thats the reason it isn't used. Blizzard approved maps can use this feature though ...but those are only created by blizzard.
You could, and you can also open e-mails with virus attachments. What this does prevent is mass speading in a few days of a virus. Think of how quickly new versions of DOTA spread Bnet... if someone disguised it as DOTA and then executed the save code in the map initialization.... massive damage.