If you live in Gmail, but don’t always have a broadband connection available, today should be a happy day for you. Google is rolling out a new system for letting Gmail users access their accounts offline. Google will cache your messages on your system using Google Gears. You’ll be able to open your browser to Gmail.com, see your inbox, read and label messages and even write replies without a Net connection. Your messages will send once your system reconnects to the Web.
The system is beta (of course) and accessible through Gmail Labs. But it won’t be immediately available to everyone – Google is parsing out access as it experiments with the new feature. I don’t have access to the new feature yet, so I’ve still got lots of questions. But Google’s post makes it sound like the experience will be almost indistinguishable from using Gmail normally.

“Gmail uses Gears to download a local cache of your mail. As long as youre connected to the network, that cache is synchronized with Gmails servers. When you lose your connection, Gmail automatically switches to offline mode, and uses the data stored on your computers hard drive instead of the information sent across the network. You can read messages, star and label them, and do all of the things youre used to doing while reading your webmail online. Any messages you send while offline will be placed in your outbox and automatically sent the next time Gmail detects a connection,” Gmail Engineer Andy Palay wrote.

There will also be a “flaky connection mode” that’s supposed to give you the best of both worlds. It’ll assume that you’re disconnected and use the local cache to store your data, but whenever your connection is working, it’ll sync with Google’s servers in the background.

This all sounds pretty good, but here are my questions:

How much will Gmail cache?

Just my inbox, my entire 6.2GB mail file or something in between? I work pretty hard to keep my inbox clear, so I hope that it’ll cache more than just my inbox.
How extensively can you search?

The biggest reason I use Gmail is that I can find a message I got two years ago in just a few seconds with the right search terms. But depending on just how much gets cached, your search capability could be severely limited.
Will you work the same way in Gmail whether you’re offline or online?

That’s certainly the way Google makes it sound. If so, that’ll be a big step forward from other attempts to bring webmail offline. You’ve long been able to access your Gmail account through a client like Mozilla Thunderbird. But that doesn’t give you all the Gmail functionality like labels. Yahoo Mail has offered offline access since last summer using Zimbra Desktop. But that also involves using a client on your desktop. For offline access to Windows Live Hotmail, Microsoft suggests using their Mail client software.
Is Gears up to the challenge? Google launched this system for creating offline access to Web apps nearly two years ago. For a long time, the only apps that used it were Google Reader and to do list Remember the Milk -- an indication that developing for and implementing Gears wasn’t quite as simple as Google would have you believe. In fact, bringing Gmail offline was an obvious use of Gears that has taken 21 months to come to fruition.

(Google also says its readying an offline version of Google Calendar, also presumably using Gears, though the company didnt specifically say that. Offline Calendar will initially be available only for users of Google Apps Standard Edition and theres no firm release date.)

Is Gears ready now? We’ll see soon. I’ll check back in once I get a chance to play with Gmail offline. And let me know what questions you have. I’ll do my best to answer them. In the meantime, you can watch this relatively lame video from your friends at Google.