Gmail Regains Offline Capabilities, Still No Threat to Exchange Online

A day after Microsoft had poked fun at its major competitor for Office 365 with a note called “Whither art thou, Google Apps offline” that chided the Mountain View company for failing to deliver on its promise to replace the previous offline mode enabled through Google Gears, Google added the ability for its applications to work offline on August 31, 2011. It almost seemed that the two companies were in perfect step with each other, which must be a first.

Gmail is the first application to boast renewed offline access with further updates for Google Calendar and Google Docs following. All of the applications are in beta status and access for Google Docs will remain read-only for now, which lessens its usefulness somewhat. Google Calendar functions as you’d expect, with the ability to answer incoming meeting requests or schedule new events.

Gmail’s offline mode is a separate HTML5-based application available from the Chrome store that you can launch in a new Chrome tab if you lose your network connection. The application installs without any difficulty (some reviewers have reported that they were forced to close Chrome before they could install the new application; I didn't encounter this problem) and naturally, because it is a Chrome application, Gmail offline has the good taste to ignore all non-Chrome browsers.

Surprisingly, Gmail offline uses a different interface from its online cousin. For example, any Google Labs extensions are not loaded, probably because some might not operate when offline. This is because the interface is based on the Gmail application built and optimized for tablets. Its look and feel will be familiar to anyone who has seen something like the iPad mail application.


Gmail offline uses a background application to populate a local cache. When needed, you can switch to working with the cached data through Gmail offline. An algorithm that attempts to figure out what conversations are potentially needed offline is used to select messages to download into the local cache. As most people need access to recent email that means that an average user ends up with approximately 500 messages or approximately one week’s email. In addition, draft messages and active conversations (those that have had an entry in the last week) are downloaded. Intelligent filters block the download of deleted messages and spam unless deleted messages are part of an active conversation. It’s likely that this algorithm will receive a fair amount of tweaking in the future to make it more effective for average users. Google also says that they will make changes to allow users to exert more selective control over data so that you could, for instance, download all messages from the last year.

The transition from offline to online access works smoothly and without problems. A small indicator shows up when the network state changes so that you know that you’re now online or offline. Status messages also show up when the application is synchronizing data.

Google is careful to point out that email data should never be downloaded onto shared computers due to the potential risk that it might be read by someone other than its owner if they can access the computer and launch Chrome. Google also notes that it’s the user’s responsibility to remove the email data if they need to sanitize the computer—removing Chrome does not remove cached data. All in all, it’s a pity that the email data isn’t better protected.

Although it is unfair to use Outlook (when configured in cached Exchange mode) as a comparison because it’s a much fatter feature-rich application than Gmail offline ever aspires to be, it’s also useful because many people are familiar with Outlook. So we can say that:

  • Background synchronization is used by both applications to keep local caches updated
  • Gmail offline is currently much more selective about the data that it downloads. Outlook downloads data from every folder in the server mailbox to create a slave replica on the PC in its OST file.
  • Outlook protects the OST by only allowing clients that can connect to the server mailbox to open the file. In other words, if you haven’t the necessary credentials to access the mailbox, you can’t open the OST. By comparison, PST files can be opened by any Outlook client, which is one of the reasons why I hate PSTs.

Even though Google might feel that they have delivered a competitive edge to Gmail over the must-be-online Outlook Web App (OWA) as used in both Exchange on-premises and Office 365 deployments, I don’t think that the folks in Redmond will be too worried. After all, when you think of it, relatively few people use OWA as their exclusive email client as the vast majority of users connect to Exchange with some variant of Outlook. All versions of Outlook since Outlook 2003 support cached Exchange mode and are perfectly capable of delivering an excellent offline experience (of course, you’ll need Outlook 2007 or Outlook 2010 to connect to Office 365). And the people who are restricted to the kiosk plans offered by Office 365 and therefore must use OWA are usually employed in locations that are always connected to the network such as factories and offices and have no need of offline mode.

Don’t get me wrong. I think that restoring offline access to Gmail is great and I know that I’ll use it in the future. My only regret is the continuing inability of Google to deliver a really integrated email and calendar client that might restore an element of competition and force the Microsoft Office team to innovate faster. Then again, some people would say that Outlook 2000 is plenty powerful enough and has enough features for anyone to cope with, unless of course you want to connect to the cloud…

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