Thanks, Duncan.
I had seen and tried that trick but no luck. It appears that if the body of the email is a string literal or even just starts with one (or from your example, includes one between variables), it preserves any whitespace you might have put in for code formatting. But if the only thing in the body is a variable name, only the value of that variable is inserted, none of the preceeding whitespace. So
#Chr(0)#Hello World#Chr(13)#
would be useful for eliminating the leading whitespace, but
#Chr(0)##variableName##Chr(13)#
doesn't have any effect because the leading whitespace was not included in the first place.
