Add Library folder to Spotlight privacy folder except Mail/MailData having some search/index problems with Mail app on old Mac OS.

How can I put ~/Library into spotlight privacy (in order to not index) except ~/Library/Mail

Mac OSX 10.8

at the moment I just explicitly select all folders but Mail under Library into Spotlight privacy part. Not so nice...
Another workaround..
move Mail folder out of Library and use symbolic link
then I can just add ~/Library into spotlight privacy part

$ mv ~/Library/Mail ~/Mail
$ ln -s ~/Mail ~/Library/Mail


index/search in Mail app will work.