MailTags 3.1 - Smart Tagging for OS X Mail 6

MailTags, the OS X Mail add-on for tacking emails with labels, projects, tickle dates, tasks, notes and what not, now not only works smoothly with OS X Mail 6 (and Reminders as well as Calendar alongside it), it comes with a sweet new display integrated in the message's header area and more classy color-coding, too:
›› MailTags lets you add tags, keywords, notes and due dates to emails in Mac OS X Mail and integrates them with search, rules, smart mailboxes, Calendar, Reminders and project-management software for near-perfect and semi-automatic custom email organization. (Mac)