Hi Jani, thank you for your help, you helped in the right direction. All mails tagged with some of those unwanted tags was also tagged spam. And spam is configured to not show up in normal searches, that's why I was unable to find them. Now all those tags have been removed, and it even seems to speed up searches, great. Kind regards, Ingo -- View this message in context: http://notmuch.198994.n3.nabble.com/remove-unused-tags-from-the-database-emacs-ui-tp4027748p4027750.html Sent from the notmuch mailing list archive at Nabble.com.