Since I upgraded to Sierra 10.12.3 the Mail.app search function doesn't work anymore. I have 8 email accounts and when I type something in the search field in Mail.app I get nothing. Funny thing, I can view the emails from Spotlight. So my suspect is about a bug on the app. I tried to: - reinstall the combo update 10.12.3 - delete all envelope files in Mail library to reset the indexing of the mailboxes - I rebuilt the mailboxes - removed mail from spotlight from system prefs to re-enable later - deleted all the accounts to reinsert again - reset completely mail app to reconfigure from scratch I miss only to reinstall the entire OS, but since it's painful...I wanna ask if anyone has the same problem. I'm on a MacBook Pro 15" 2016. My girlfriend has the same model but 13" and she has no issue.