Evaluate

You need to do as Dan suggested. Store the email bodies in separate files and store the file location in your database. This doesn't prevent you from, as you say:
"...so editing is very fast and easy - with menus."

Just use <cffile> to read and write the contents of the files. And when you're sending your emails, use <cfinclude>

You can't dynamically evaluate coldfusion code, which is what you're trying to do. You want to be able to do something like this:
Evaluate("<b>Hello #firstname#!</b> Thanks for requesting our newsletter!! Today's date is #now()#")
That won't work, as you've found out. The only way to accomplish this currently is to write that string to a file, then <cfinclude> that file.

What happened when you simply outputted the html stuff from your db without trying to evalutate it?

You are probably better off storing the info in files and putting the file locations in your db. Then you can use things like cfsavecontent or cfinclude and things will just work.