Getting fixed-width font for Gmail messages

Gmail labs has a feature to display a message in a fixed-width font, but you have to manual select it from a menu each time you want.

The following is a quick CSS userContent.css hack for Firefox that will cause message content to always display in a fixed-width font:

@-moz-document domain(google.com) {
.ii {
  font-family: monospace;
  font-size: 75%;
}
}

I use "monospace" since it will use what I have specified in my font preferences in FF. The key item is the ".ii" class.

The only negative side-effect is that non-text messages, like HTML, will have the default font be monospace. However, I'm currently willing to live with that limitation.

I posted a suggestion on the Gmail labs group for Google to define CSS classes based upon content media-types, so CSS settings can be constrained for a given media-type. Who knows if they will ever do such a thing.