I considered this, but it seemed to be worse to have these be "Include K-9 User-Agent header" (checked by default) and "Specify current timezone in headers" (checked by default) in the Privacy pane.

Having these two checked by default in the Privacy pane gives the user the incorrect first impression that all of their settings are already private, because everything is checked...

If you're sure the negation is worse than this potential confusion, then I can change it though.