Sparrow is a New Email App for Mac OS X

Sparrow is a minimalist mail application for Mac. It was designed to keep things simple and efficient.

The current beta only supports Gmail; however, there are plans to bring IMAP support and more.

The user interface is similar to Tweetie for Mac.


FEATURES:
● Threads: Quickly flick through threaded conversations on your mac like never before.
● Not so minimal: See your mails the way you want. Quickly glance at the preview. Read it in a new window or open the right pane to enjoy Sparrow's full potential.
● Notifications: Growl is integrated for notifications addicts.
● Multiple Accounts: Seamlessly switch between your mail accounts.

Read More [via Edwin]