The only real interface is to create search folders that search by Tag on the server. Dovecot indexes everything behind the scenes, so it's reasonably fast. Sa

The only real interface is to create search folders that search by Tag on the server. Dovecot indexes everything behind the scenes, so it's reasonably fast. Sadly, a full on "here's a hierarchy of tags, just display mail by tag" mail reader doesn't exist to my knowledge outside of GMail itself :(