I use an AppleScript to periodically archive old mail, which is then moved to an external drive. Previously, I was exporting the messages to .txt files, which were searchable. However, I would like the enhanced formatting of messages to be preserved, so this time I left them as .emlx files.
Is there a way to force Spotlight to index these "orphaned" .emlx files? It's not indexing them now (and I tried the trick of adding/removing the folder in the Privacy prefs).