OK,
I have a solution which fixed everything. Related to Spotlight operations...
Apparently, Mail.app is using Spotlight for indexing (since Mavericks) and if Spotlight is not running on your drive with Mail data, no smart folders stuff (and other issues)...
I checked using MacPilot and Spotlight was not running on my main drive. I tried adding and removing the drive from Privacy window in Spotlight preferences, nothing. Even MacPilot was unable to re-enable the Spotlight there. Hm, weird. So I went the command line route and found:
http://apple.stackexchange.com/questions/24401/spotlight-reports-indexing-and-se arching-disabled-in-lion
Turns out, somehow during installation and migration of my user data onto the drive, this happended:
... I reexamined the directory listing for /
and found a hidden file .metadata_never_index
in the root directory. I removed this file and was able to turn spotlight on again with mdutil -i
on /
.
As said, I removed the .metadata_never_index - you need to be root for that and even use sudo:
bash-3.2$ cd ./
bash-3.2$ sudo rm .metadata_never_index
And my Smart folders are miraculously up and running... And Spotlight is actually more useful now also :-)