About working offline
In Outlook, you can work on e-mail, calendar, and other items even if Outlook is not connected to your network or to the Internet. For example, you can read any e-mail messages that were downloaded to your computer before you went offline. Outlook stores copies of messages that you have received in the Office database, and you can access them even when you are not connected to the network or Internet.
If you have an Exchange account, Outlook also downloads a copy of your organization's address book. This allows you to address e-mail messages and create meeting invitations while you are offline.
If you create a new message or meeting while you are offline, you can click Send to store the message in the Outbox. The message is sent the next time that you go online.
The Help system in Office for Mac 2011 can be accessed whether you are online or offline. However, when you are online, you can access more extensive and more up-to-date information.