After using Sparrow for a while, I have decided to switch back to Mail.app. However, even after setting my default email client to Mail.app, all my message: links (for example, from messages dragged from Mail.app into Things) were opening in Sparrow. After some experimentation, I figured out what happened: I switched the default email client from Sparrow to Mail using Mail's preference panel: Apparently this switches the application for the mailto: protocol, but not for message:, nor for .
