I’ve been writing a form letter in LaTeX with WikiBooks’ guide. To my dismay, the default formatting yields a huge top margin.

Fortunately, Eliezer Kanal at Shady Acres has found the fix in the `\opening` section within `letters.cls`. All I had to do was manually `\setlength` the `\topmargin` above the printing and the \textheight of the main text box, and it formats correctly.