When atebits, LLC first released Tweetie for Mac back in November 2008, it was pretty much the perfect Mac app. Simple, elegant, and attractive, Tweetie folded Twitter into a silky alloy of innate functionality. But when Twitter’s functionality expanded along with users’ expectations of what Twitter should be used for, Tweetie failed to evolve.When that happened there was still nothing wrong with Tweetie, per se: in many ways, it was still the most perfectly actualized Twitter client to ever hit the Mac. The trouble was, when you used Tweetie, you could only use Twitter as if it were still 2008. To use Twitter as it was now, you needed to download a more robust, complicated and confusing client, like TweetDeck. So everyone loved Tweetie, and everyone prayed for an update, and on many people’s hard drives, Tweetie remained… a chunk of amber that crystallized inside itself what Twitter once was, but which distorted the social network when used as a glass to look upon its current reality.Sparrow for Mac is a lot like Tweetie, in both the ways it is supposed to be and the ways it is not. Depending on how you use email, that might be exactly what you need… or enough to make you admire it for its beauty, but ultimately gnash your teeth and plunge right back into Eudora.Like Tweetie, Sparrow is designed to be minimalist and aesthetically pleasing… an approach that is a breath of fresh air in an email client. Sparrow’s triple-paned layout corrals all of Gmail’s major sections in the left-most column, allowing you to easily switch between your inbox, your drafts, the messages you’ve starred for later, your spam and search. The second column shows you a list of your latest emails, threaded into conversations, while the third pane (which is collapsible) shows you both the full conversation of a given thread and allows you to quickly reply within the same pane.What Sparrow’s approach does really well is eliminates extraneous windows. Unless you are composing a new email message, using Sparrow in its more compact collapsed mode or pointedly tell Sparrow to open a new window for a reply, Sparrow always keeps you within its triple-paned borders. For someone like me, who all too often finds himself closing dozens of open emails after a day or two in Mail.app or Postbox, Sparrow’s reluctance to split itself between windows as a compulsion of digital mitosis is much appreciated.Everything about Sparrow is elegant. The Quick Reply feature, for example, allows you to dash off instant responses almost as if they were tweets. This is functionality that is present in my other favorite mail client for Mac, Postbox, and one that I’ve found impossible to live without. Sparrow’s take on quick reply is nicer aesthetically, if identical in the details. Handling multiple email accounts is as easy as clicking on the user icon assigned to that account in the left-hand pane. Attachments are handled inline, just drag and drop. Labels can be created and assigned effectively; switching between Gmail folders is as simple as clicking through a drop down. Even Snow Leopard’s built-in Quick Look functionality is supported: simply tap space to preview any message’s attachment.Like I said, elegant. But for some users, the problem will inevitably end up being that elegance is not the same as fanciness, and Sparrow eschews the fancy features of the more sprawling clients like Mail, Thunderbird, Eudora or Postbox. You won’t find the ability to annotate inbox messages here, or mark contacts as favorites, or search through messages with granularity down to the attachment byte. You can’t change the layout, or even pick and choose between signatures for any given email account. The list goes on.For most users, that’s a good thing. Sparrow’s not trying to be all things to all people, which is what email has evolved into over forty years. It’s trying to make the hundreds of emails you get each day more manageable not through giving you ever more complex tools to deal with them, but rather by treating them like tweets… messages that can be responded to at length with just as much zen as they can be ignored.Even for non-power-users, though, Sparrow occasionally seems to have skimped on small features. There’s no built-in ability to sort your inbox by read status, for example, nor is there a way to mark all emails as read. Sparrow’s contacts are all plucked from your Google Contacts list, but there’s no way to manage them in-program. Similarly, there’s no way to create new filters and smart labels within Sparrow. There’s no support for Gmail’s priority inbox. All of these functions are accomplishable, but only if you open Gmail in a browser.Whether Sparrow is right for you comes down to a couple of things. The first is whether or not you use Gmail and embrace its conceits: threaded conversations, archiving, labels instead of folders, etc. Sparrow doesn’t work with anything besides Gmail accounts, and while they promise support for other IMAP accounts in version 1.1, the program is so thoroughly infused with Gmail DNA that I wonder if IMAP support will ever be anything besides a half-baked afterthought.The second: how seriously do you take your email? How much can you go with its flow? Power users will be driven mad by the lack of sophisticated mail wrangling functionality in Sparrow, but that’s the whole point. Sparrow wants you to treat your inbox like a stream that can be dipped into, not an ocean to be tamed; it’s the equivalent of skipping stones, not piloting a submarine.So is Sparrow right for you? At $9.99 on the Mac App Store, with an ad-supported Lite version coming soon, it’s certainly worth an examination if you use Gmail and would like to make wading through your emails a lighter, breezier and more zen-like experience.Ultimately, though, Sparrow treats email a lot like Twitter, which is a four-year old micro-blogging medium still in the process of evolving. It’s a presumptuous move on the part of Sparrow’s developers, and one many users will just never be able to get beyond, either because they need more functionality from an email client… or, after decades of using email one way, they just can’t believe that they could be more productive treating it more ephemerally.