Wrapping text automatically option doesn’t seem to work

I’ve set Outlook’s “Automatically wrap text at character” option to 40 instead of the default 76 but it doesn’t appear to do anything.

When I compose a message, the line still goes on forever and doesn’t break into a new line at character 40 at all. The same is true for the received message.

Why isn’t it working or what is this option supposed to do then?