While letter and E-notes have monospaced fonts (last I checked, at least) they have much shorter line limits than SIC does. I want to say it's something like a 50% difference between the two. This prevents a good number of designs from effectively being shown to other players or NPC's.
I don't know if it's possible to change just the style sheet for the gridmail terminal html file, or if that's not isolated from the rest of the grid. I would imagine there might be some breaking of things if the font for all of the grid was changed to monospaced. I'm only asking that we update the font in the gridmail portion of the grid.