March 26, 2007

Zimbra, which was one of the first to messaging providers to mashup email with the web, is about to introduce an alpha version of an offline client. The idea of course is that while you’re trapped on a plane, wouldn’t it be nice to work with all the email that flooded your box before you took off? 

What it means is that, no matter how thin and functional your Ajax client, at some point you’ve got to bite the bullet if you want to work untethered. So Zimbra has developed a persistent client that you download and install. Depending on the OS, the file runs between 20 – 50 Mbytes in size. Once you install it, you download your inbox so it sits on your machine. It’s stored in an Apache Derby database, which is the embedded open source Java database formerly known as IBM Cloudburst. And the client will automatically resync with the server when it comes within range of the ‘net (you can also prompt an update). And like the existing Zimbra online client, the desktop can feed your email into a Microsoft Outlook client.

As any email veteran will attest, mailbox file sizes can grow quite large. And while Derby was never designed with scalability in mind, it can store more than you think, according to Zimbra marketing vice president John Robb. In a pre-alpha version of the offline client, Robb’s inbox was 4.9 Gbytes; he added that some colleagues in the office who were also testing the pre-alpha version had even larger files, and Derby worked just fine.

As is the case with any early release, there are obvious features missing. For now it only includes email and the address book. Calendar will come later, as will support for Zimlets, which are declarative XML libraries that can be used to help piece together your own mashups. And if you don't want to carry your entire inbox around, for now that's not an option.

With the alpha version available now, Zimbra hopes to have the full 1.0 release for general availability by the end of the year.

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