Since it works fine as it is, I rather don't want to potentially break 
some implementations. It's not meant for human consumption anyway.

Should ingo/lib/Script/sieve.php put :text explicitly into body 
checks?  RFC 5173 says that body transform "can" be applied (odd 
word-- not may or should) and that :text is the default (or that is, 
it "can" be the default?).  Cyrus sieve does default to :text.  Still, 
adding :text would clarify to humans reading the script that only text 
parts will be searched.  One-line diff below.

Forget this if there are sieve implementations that don't do body 
transform at all that would break on being told :text.


--- 2125,2131 ----
       function toCode()
       {
           $code = 'body ' .
+           ':text ' .
               ':comparator "' . $this->_vars['comparator'] . '" ' .
               $this->_vars['match-type'] . '