In order for tags to be really useful you need to implement bulk tagging as a matter of urgency. Tags are great, but what about assigning them to past emails and email conversations? Surely you are not expecting users to go through their old emails one-by-one to add tags? I use email tagging already and want to migrate already tagged emails in Apple Mail (they show up as labels in Gmail). While I can select individual old emails and tag them with Mailbutler, I cannot do this with multiple emails. This seems to be a simple feature to implement, but a vital one to get your loyal Mailbutler users to really use tags!