One of the major changes coming up in a future version of Zimbra is a rethinking of the offline experience – how do you use Zimbra when you’re not connected to a network, or when your connection cuts in and out during the day? As we all become more mobile, this is an important concern.
Today, Zimbra Desktop is the way to use Zimbra when offline – and it’s done a good job at providing consistency between the online and offline experience. But we think we can deliver a faster, smoother and more efficient offline experience by re-architecting Zimbra Desktop from the ground up.
This change describes the work that we are doing for supporting the offline experience – to be available in a future version of Zimbra.
On a side note: Nothing discussed here affects third-party client support – such as Microsoft Outlook or Apple Mail, iCal and Address Book and standards-based clients (POP, IMAP, iCal, CalDAV, etc.)
The concept behind the Zimbra Desktop was to create a consistent experience whether you’re offline or online. The look and feel should be the same. This is in contrast to environments where the browser-based interface is really different than the local email client – say, using Microsoft Outlook and Outlook Web Access.
In the current Zimbra Desktop, we’ve done this by building the entire stack on the desktop – web server, application code, database capabilities.
The technologies available have evolved. For example:
The client devices have changed and expanded to include a growing number of mobile phones and tablets. Native client frameworks can do functions such as storing, synching and accessing local data very efficiently.
- Although still under development, HTML5 is maturing and offers a new set of offline capabilities. It will eventually subsume earlier versions of HTML.
So our team started evaluating ways to use these technologies to make the Zimbra Desktop better – without re-engineering core capabilities already available elsewhere.
The New Zimbra Offline Architecture
We’re excited about the possibilities of using HTML5 to support a seamless, browser-based offline experience. But we’re also looking at ways that the native client platforms can supplement the browser environment, for example:
- Notifying you of new email or appointments when the browser isn’t open
- Storing and indexing data for local search and access
- Synchronizing data with the Zimbra server
We’re moving towards a hybrid architecture that will combine the best of both worlds – browser-based simplicity with native capabilities for functions such as notifications, storage and indexing.
The team is still sorting out several key design issues, such as: how will we handle viewing attachments when offline? How much storage is the right amount? How do we figure which emails and attachments to store locally? Most importantly, which features do we need?
End user requirements: consistency
The most important requirement is to deliver a consistent experience, whether you’re online or offline. Clearly, the offline environment cannot support everything you have online – the amount of data needed would be prohibitive. And we need to balance functionality with performance.
Consider a case: you’re commuting on a train and the WiFi connection cuts in and out while you’re working. Our objective is that the transition should be seamless. At a minimum, offline capabilities should include:
- Reading emails and working with your calendar
- Viewing attachments
- Composing emails (with autocomplete for addressing them)
- Automatic synchronization when you reconnect
Administrative requirements: security and control
For administrators, the offline experience brings the challenge of data residing on devices outside of their control. So we’re thinking hard about their requirements for the offline experience as well, which may include:
- Remote wipe
- Policy-based controls on attachments
- Data retention policies applies to data on the remote devices
In a future version of Zimbra, we’ll switch from the current Zimbra Desktop to the new offline experience. Look for more information as we come closer to future Zimbra releases. In the meantime, we’d welcome your feedback in comments here. Please provide comments here, on our Twitter feed, Facebook page or start a thread in our Zimbra forums.