Comment 86 for bug 10883

Just reminding you that IE has that on compose window (Format menu) and it's
easily accesible for both new message compose and for reply. Mozilla has only
the shift-click approach (that I wasn't knowing about until I came here) that,
fortunately, works for replies too.
Since html mail is a commodity these days, i'm guessing most users will be
disappointed because now we don't have that option in the UI.