> 	How can I increase Kmail's HTML font to a readable size?  (See attachment.)  
> There's no line item in Settings -> Appearance -> Fonts -> Apply to: for 
> Message Body - HTML.
> 	Yes, yes, I know; HTML can have multiple font sizes.  What I need is some 
way 
> to scale them all by some percentage, or something.

Settings > Configure kmail > Appearance

Kate The Great and Terrible!