For Thursday’s iLounge Deal, you can get a lifetime subscription to MailButler Professional for only $34.99 — that’s 97% off the regular price. This highly-rated plug-in for Apple Mail lets you turn it into a full-featured personal assistant to increase your productivity. You can mark your e-mail messages as to-do items to ensure you never forget about important tasks, snooze emails to get back to later, track outgoing messages to see…