With the coming new Exchange version, called Exchange 2013, Microsoft has introduced a new feature on OWA (Outlook Web Access).

This feature, called OWA Offline, allows you to keep access to your mailbox using OWA even if you are not connected to your Exchange mailbox; in the same way than Outlook cache mode.

On this post, I’ll show you how to use it. There is nothing to do on the server side (to enabled the feature).

You can watch this video demo http://youtu.be/8n7r7XfhU7g



To be able to use this feature you must match the following requirements

  • Compatible browser
    • Internet Explorer 10 (included on Windows 8 or available as download for Windows 7)
    • Safari 15
    • Chrome 16
  • Exchange version
    • your mailbox must be hosted on Exchange 2013
    • OWA access must be hosted by Exchange 2013 CAS server
    • OR you can use Exchange Online as the next major update for Office 365 will includes Exchange 2013


Use OWA offline

If you browser is matching the prerequisites, the first time you will connect to your mailbox using OWA you will have a request to enable browser cache (for IE, a status bar will appear at the bottom)


Click on YES. This request will not appear anymore later.

Then open the Options menu and choose Use mail offline


Then OWA will synchronize your mailbox: by default, only Inbox, Sent items, Calendar and Contacts will be synched. If you want to keep more folders available while offline, just browse them.


The first time you will enable OWA offline, the system will request you to confirm you are the only one to use the computer on which OWA offline will be enabled. Indeed, the OWA offline cache is not user defined and if you are sharing the computer with other users, they will be able to see your mailbox content.


That’s it, OWA offline has been enabled.

When you will be disconnected from your mailbox, you just have to open your browser and type your OWA URL to logon and access your mailbox while offline.

While offline, you will see a short message informing you the last time the folder has been synched.


You can create new email while offline, and when you will be connected again, your mailbox will be automatically resynched (new emails will arrive, outgoing emails will be sent…)



Clear / Disable OWA offline cache

OWA offline is using a new feature introduced with IE 10, called Cache and databases.

To clear the cache, or disable it, go to Internet Options\General tab\ and click on the Settings button available at the Browsing history section and then open the Caches and databases tab.

From this point, you will be able to clear existing cache or disable the feature.

Be careful, if you disable it OWA offline will not be available.