Gmail offline: A guided tour

Wondering how Gmail offline works? Here, we walk you through it.

In short, people familiar with Gmail already are mostly familiar with its offline incarnation, which Google said it's releasing gradually to its users in coming days. The biggest difference is of course that you can't see new messages, and e-mails that you send are merely queued up until they can be delivered when a network connection is re-established.

Gmail uses Google's Gears technology, which among other things lets browsers store data on a computer in what's called a local cache. I'm using Firefox 3.1 beta 2, with which Gears isn't compatible, so to access Gmail offline I used Google Chrome instead, which has Gears built in. Since Gears is a relative rarity, though, most folks will have to install it first, which Google walks you through.

There are some limitations to offline Gmail: Only about 10,000 messages will be downloaded--the newest and most recently used. You can't use the contacts tab to manage your connections, though e-mail address autocomplete works so you won't need to worry about remembering e-mail addresses. You can't include attachments on new messages. It's only available in Gmail for English speakers.

But overall, it's certainly worth it if you're ever on a plane, taxi, train, vacation retreat, or coffee shop with an overstressed connection.

How do you use it? First things first. In the Gmail settings section, go to the "Labs" tab, click the "enable" button next to Offline Gmail. Then go all the way to the bottom of the page and click "Save Changes." This is an experimental feature, and Google warns they've occasionally seen issues keeping the local cache in sync.

There's more to be done to set it up, though. Go back to your in-box, then click the "Offline 0.1" link in the upper right corner. That'll walk you through the next stage of setup, including the setup of Gears if you don't have it running yet.

Next comes the explanation of what you're doing and the warning not to install offline Gmail on a public machine.

Then comes the permission phase. You're granting Gmail access to Gears, which means the software is granted access to your hard drive.

Do you feel you don't have enough icons in your life? Is your desktop just not cluttered enough? If so, now's the time to let Gmail sprinkle some more icons around. I actually don't mind this for valued applications: on Windows I assign a keyboard shortcut to the icon so I can launch it with a Ctrl-Alt-G combination. When you launch Gmail off the icon using Chrome, it fires up the application with no tab and navigation bar, so you get maximum screen real estate for the application; clicking links opens them in a new browser window.

Next comes the synchronization process. Depending on your in-box size and network connection, this could take awhile. And unfortunately, if you enable offline mode on a separate browser--Internet Explorer, for example--Gmail has to download the whole shebang again.

Happily, Gmail still can be used while you're creating the cache, because Gears is multithreaded--in other words, it can walk and chew gum at the same time.

The synchronization process is interruptible. Gmail tells you how far back into your archive it's delved and how many messages have been downloaded so far. The database is optimized for about 10,000 messages, and searching them is swift, even if it returns incomplete results compared to Gmail's performance while connected to your full archive.

Once the messages are done, Gmail tackles the attachments. You can view attachments when offline, but you can't include attachments in new e-mail you create while offline, at least for now.

The control panel in Gmail settings shows how far back Gmail's offline archive goes. It also tells you which tags it includes, which is handy--if you want all messages from your folks in the archive, label them "family" (I have my account set up to apply that label when the messages arrive from various e-mail addresses). Any label you've clicked on will be archived offline. (In this image, my labels have been blurred. No peeking!)

If you're offline, Gmail detects it automatically. Clicking the gray circle-with-a-bar icon that indicates no network will produce this pop-up that lets you manually try to reconnect. The status bar--whether online or offline--also lets you enter the intermediate "flaky connection mode," which is designed for times when your network access is intermittent. With it, Gmail will try to retrieve new messages and deliver the ones you've instructed be sent, but won't get too ruffled if the network isn't up.

After this, you're set up for offline Gmail. All the rest of the interface is the same as online: messages can be read, starred, labeled, and archived; search and conversation view work with the messages in your archive; and new messages can be written. I'd like contacts management, but overall, the experience is good and a big improvement for the application.