I'm as sad as anyone to see that I let more than a month go by without committing to the notmuch repository. But I've just now committed the much-desired folder-based search feature. This should be a handy feature for people bringing mail in from a system that stores information in the directories in which mail is stored, (one common case is users fetching mail from gmail via imap---in this case all gmail tags will be represented as directories). Someone bringing in mail from such a system might want to migrate from information in directory names to instead be information in notmuch tags. That might look something like this: notmuch tag +important folder:important Or it might be useful to run on several directories: for dir in *; do notmuch tag +"$dir"; folder:"$dir"; done etc. Please note that with the code in git currently, only newly incorporated mail will be searchable via the "folder:" specification. So if you're wanting to search your entire email collection, you may want to rebuild your entire notmuch database. As a reminder, that process is something like the following: notmuch dump > notmuch.dump rm -rf ~/mail/.notmuch # Careful with this! Have backups in place! notmuch new # Of course, this can take a long time notmuch restore notmuch.dump Before the next release, I plan to increment the database version so that users will be notified of the need to do an upgrade like this. (But before I do that, I plan to implement a few more database changes---and some of them are likely to be much more invasive than this one). Have fun out there! -Carl