Simplify email categorization - it will be easier for you and others to manage mail. Define the set of prefixes for all emails you send or let SubSwitch to autodiscover it. While writing insert prefix to the title - choose one from your set.
This is an extension function that classifies emails into multiple buckets using AI(the Bayesian filter) and tags them.
Add toolbar for toggling tags.
Enable you to arrange the tag sequences in their listbox.